Importance of sadhusang is mentioned in all the scriptures. Tulsidas has written about how important sadhusang is, even if it is done for fraction of a second. Tulsidas's teachings and books like Ramayan are frequently heard here, so it is not difficult for you to understand what he has said.

ek ghadi, adhi ghadi, adhe me puni adha,
tulsi sangat sadhu ki hare koti aparadh

If you consider 'ek ghadi' as one hour then 'adha ghadi' is half an hour and half of that- means fifteen minutes, Tulsidas says if you associate with a bonafide sadhu even for just fifteen minutes, sins of your crore and crore births would be vanished. That is the importance of associating with a bonafide sadhu. But it is very rare to get a bonafide sadhu. Shankaracharya says, kshanam iva sajjan sangati rekha, bhavati bhavarnave tarane nauka. If you get association with a real sadhu even for a fraction of second, it would become a boat for you to cross over the ocean of this material existence.

sadhusang sadhusang sarva sastre kaya,
lav matra sadhusange sarva sidhhi haya

It is the injunction of all the scriptures that simply by a moment's association with a sadhu, one can attain all kinds of perfection. There is one more quote from Tulsidas. I request you to hear it very attentively. I do not have good command over Hindi language, but in North India, Maharashtra etc. I have to speak in Hindi. In Banglore and Kochin, speaking in English is more common. Sometimes in Mumbai also, I have to speak in English. When I go for preaching in North India, I heard many times organizers of the programs quotes, what Tulsidas has said, suta dara lakshmi paapi ke bhi hoya, santsamagam harikatha tulsi durlabh doy. Wherever I went, I heard it. A bonafide sadhu is rare to be found in this world. If you want quality, you cannot get quantity. What is the population of Hyderabad? It may be fifty crore? One good character person can bring welfare to thousand and millions of people. However, all the characterless people together cannot bring welfare to even a single person. There are six billion people in this world, but if all would be characterless then what welfare can they bring to others? So what is more valuable, quality or quantity? One scientist can invent a medicine which can help six billion people of the world. If you ask for quality, you cannot get quantity and if you want quantity then you have to compromise on quality. You will not get them together. So it is said here, santsamagam — association of a sadhu and harikatha, you will not get everywhere. Who can speak hariktha? One who knows hari (the Supreme Lord), can only speak harikatha. I heard organizers of spiritual programs speaking, “All the saints have arrived, this place has become a triveni (confluence of three holy rives), you take a dip in it and you will get eternal welfare.” My question is they explain only the first line, santsamagam harikatha tulsi durlabh doy — association of a sadhu and harikatha are very rare, but they do not comment on the second line, suta dara lakshmi paapi ke bhi hoya — even sinners can give a son, a good wife and wealth.” When you comment on something, you have to explain it completely. They explain only the half of it and not the other half. So, here I will try to explain it.

You should not to go to a sadhu for getting perishable material objects. You should not ask for a son, a beautiful wife or wealth from a sadhu. If you have desire for those things then you may go to the sinners, they also have got wealth and everything. Tulsidas has said this instruction in his second line. Why do not you speak about it? You have to speak about this also. A bonafide sadhu cannot give you material objects. He would never deceive you. He would never advise you to jump into fire to get burnt and die. It will never happen. But there are some so called sadhus also present in the society. For instance, in Kolkata many people bet their money on horse race, which is a kind of gambling. They go to such a person to get advice on which horse they should put their money on so that they can get more benefit. Now if that particular horse wins the race then those people would consider him a great sadhu. But Tulsidas says he is not a sadhu. He is giving you some temporary material things for his own benefit. He is not called a sadhu. Just by wearing white or saffron clothes, one cannot become a sadhu. Therefore our Gurudev instructed us,

muktānām api siddhānāṁ
nārāyaṇa-parāyaṇaḥ
su-durlabhaḥ praśāntātmā
koṭiṣv api mahā-mune
(Srimad Bhagavatam 6.14.5)

(Among many millions, who are liberated and perfect in knowledge of liberation, one may be a devotee of Lord Narayan, or Krishna. Such devotees, who are fully peaceful, are extremely rare)

Narayan-parayanah — a person who has concluded that Narayan is the Supreme, is not only durlab (rare) but he is su-durlabh (very very rare). There cannot be any possibility of mistakes, illusion, cheating or imperfection of senses in the words coming out from the lotus lips of Supreme Lord as He is all-knower. These propensities could be present in human beings. One who posses all the six kinds of opulences in full, is called Bhagavan. He has infinite opulences. And there is no difference in Vedas and Narayan, they are identical. Narayan is undivided Knowledge principle. He is the shelter of all the jivas. Vedas are also undivided knowledge principle, identical with Narayan. So our Gurudev instructed us to contemplate on the words of Lord and teachings of Vedas and scriptures.

Krishna-dvaipanyan Vedavyas Muni is the original Guru of all sects of people. He has divided Vedas in to four categories—Rik, Sam, Yajuh and Atharva. An ordinary person cannot do that. He has written 'Vedant ' the best scriptural evidence of the jnanis. He has written eighteen puranas—six sattvik, six rajasik and six tamasik. He has written 'Mahabharat' which includes the Gita. Even after writing so many scriptures, his mind was not at peace. So he went to Badrikashram and took shelter to his gurudev, Narad Goswami. Narad Goswami appeared there and he chastised him, “You have done an abominable thing by writing about dharma, artha and kama.

jugupsitam dharm-krite 'nusasatah
svabhava-raktasya mahan vyatikramah,
yad-vakyatodharma iteetarah sthiti
na manyate tasya nivaranam janah
(SB 1.5.15)

You have given perishable, non-eternal things. You have given pain to others. So how could you get peace?”

“I have spoken about emancipation, about salvation.”

Then Narad Goswami told, “You have done more harm, the highest harm to living beings. You have deprived them of getting highest bliss (Krishna-prem) for eternal time. You have encouraged them to commit suicide, by guiding them to merge their real self into formless brahman. You have not sung the glories of Supreme Lord.”

“I have sung His glories in Gita and Mahabarat”

“That is for emancipation not for the satisfaction of Supreme Lord. You sing His glories for His satisfaction.”

Then Naradji imparted four verses—Chatuhshloki Bhagavat (the four main shlokas of Bhagavatam) .

By contemplating on those four verses, he sung the glories of Supreme Lord after which he got the highest peace. Mahaprabhu has instructed us to listen to that Bhagavatam, the glories of Lord compiled by Vedavyas Muni, which is the essence of all the scriptures. About one thousand feet above the Badrinarayan temple, there is that place where Vedavyas muni wrote Srimad Bhagavatam. I had been there once with Guruji, It was Tibet that time but now it is China.

Mother Devahuti asked Bhagavan Kapildev, “What is trigun (three modes of material nature)?” When mind is attached to the trigun, it causes bondage and when mind is attached to the nirgun (transcendental) Bhagavan it causes the deliverance from the clutches of maya. But we have not seen nirgun Bhagavan yet. The vigrah (deity) of the Lord which we can see, He does not reciprocate with us. This material world is temporary and all relations in this world with wife, son, friends etc. are also temporary but as we have loving exchanges with them, we become attached to them. But we do not have any conversation or loving exchanges with Supreme Lord, it may be possible with a special devotee but generally with common people it does not happen so. Therefore Bhagavan Kapildev explains on how the minds of votaries get attached to nirgun Bhagavan, even if he did not have any exchange with Him:

prasangam ajaram pasam,
atmanah kavayo viduh,
sa eva sadhusu krto
moksa dvaram apavrtam
(SB. 3.25.20)

(Every learned person knows very well that attachment for the material is the greatest entanglement of the spirit soul, but the same attachment when applied to the self-realized devotees, opens the door of liberation.)

The triguṇa are sattva, rajaḥ and tamaḥ, the three primeval qualities of the external potency of the Supreme Lord. By rajoguṇa the bodies of the living beings are created, by sattva-guṇa they are sustained and by tamo-guṇa they are destroyed. The body is triguṇa because it is born by rajo-guṇa, it exists for some time by sattva-guṇa, and is destroyed by tamo-guṇa. This body is temporary. Those who are deha-sarvsya-vadi, who always remain busy with bodily affairs and engaged for bodily comforts and happiness, for them this body is the main cause bondage. It is written in the commentary that 'stri, putra, mitradau prasangam' — the relation with wife, son, friends etc. is temporary and their association is trigun. Thus the body and the bodies of people associated with it are all triguṇa. We can't see their souls, only the bodies. This body will stay for some time and then perish. Therefore, the relationships with gross bodies and exchanges with them are the cause of firm bondage. Those who are atmatattva-vid, learned, wise persons, they know this. prasangam ajaram pasam, atmanah kavayo viduh, sa eva sadhusu krto moksa dvaram apavrta. Though we cannot see Supreme Lord or He does not talk with us, but sadhu does. He talks with us. Lord Himself appears or sometimes He sends his own associates to this world. So, the same attachment (prasangam) when applied to a sadhu (the self-realized person), it opens the door of liberation.

Now the question is who is sadhu? One who is sad-parayan—who has attachment to the sad-vastu is called a sadhu. And 'sad-vastu ' is Bhagavan—purna-sacchidanand, All-existence, All-knowledge, All-bliss, ishwarah param krishnah sacchidanand vigrah, anadiradi govidah sarva karan karanam. And one who has strong love or attachment for that Govind, is a sadhu. Where will you find such kind of sadhu? If you associate with such a sadhu then you will get true result of sadhusang (associating with a sadhu).

Sadhusang does not mean merely physical proximity. If it is so, then the bugs in the sadhu's bed are associating with him. Are they getting the result of sadhusang? There was one Babaji in Chaitanya Math, who used to chant the holy name all the time. There were lot bugs in his bed. If we would have been in his place, we could never have slept even for a moment on his bed. So were those bugs associating with him?

The sadhu is always absorbed in remembering Radha-Krishna, while those bugs are always engaged in sucking his blood. They are exploiting the sadhu. This is not real association with a sadhu. Lice also suck the blood of a person being in the topmost part of his body, the head. So even by staying with superiors at superior position, it may be possible that you are not associating with them. On the other hand, you can associate with a sadhu from a thousand miles way also. Sadhusang means following the mentality of a sadhu, acting according to his internal mood or his desires.

So one should understand and follow the mood of the sadhu and not try to imitate him. Imitation is not good. If you imitate his external activities like, how he is walking, how he is sleeping etc. then that is not actual sadhusang. You have to follow the internal mood with which he is performing devotional activities. One Swamji used give an example in this regard.

There was once a peddler who maintained his family by selling caps. He would carry the caps on his head in a wicker basket. He would walk through the streets all day long selling these caps, taking his food along with him and eat along the way. He spent the day walking along the road, shouting, "Very nice caps for sale today! Price reduced! Take! Take! Take!" People would come and purchase his caps and he would thus maintain his family. He used to sell one cap in ten rupees. That time ten rupees was a big amount. In those days we used to get two kilograms of brinjal in one paisa and forty kilograms of rice in two rupees, now the prices went so high. It is called inflation. But that time people used to run their family for one month in fifty rupees only. Now one day, even though he had spent the entire day shouting, he could not get any money. Not a single person had bought anything. Needless to say, he was very disappointed. Toward the afternoon, he became fatigued from so much walking. So, he sat under a big banyan tree. Being hungry, he ate the food that he had brought with him. After having eaten, he became drowsy and began to yawn. As he was so tired, he thought, "Let me lie down for some time." He spread a bedseett on the grass beneath the tree and lay down. He placed the wicker basket, filled with caps, by the side of his head. He also kept a cap on his head and fell asleep.

After some time, some monkeys came from nearby and climbed up into the banyan tree. From the top of the tree, they could see that someone was sleeping underneath, who had a cap on top of his head, and next to him was a wicker basket-full of caps. They descended the tree and, silently, they approached the basket. Each monkey took one cap and put it on his head. In this way, all the caps were emptied from the basket. The monkeys became very satisfied with themselves by having put the caps on their heads. They climbed back up the tree and started to jump about from one branch to another with great delight, shrieking, "Kak! Koo! Kak! Koo!"

Hearing the sound of the monkeys, the peddler woke up. He was surprised to see that it was now evening. He looked at his wicker basket and saw that it was empty. "What? Not a single cap was sold but the caps are all gone! Who took them?" He looked about and saw the monkeys with the caps. "Now I have eaten all the food and have none left. If I have no food to give the monkeys, they will not return the caps." If you go to Vrndavana, there are many monkey-devotees there. Those monkeys will steal your spectacles. They will only return them if you give them some food. Now, this peddler realized that he had nothing to give the monkeys. "If they surround me, I shall be killed by them!" he thought. He became enraged and shouted, "You have taken all that I have! Why have you not taken the cap on my own head? Here, you should take it!" He took his cap and threw it at them. The monkeys saw this and, taking their own caps in their hands, threw them at the peddler below. Because the peddler had thrown his cap toward them, they also threw their caps toward him. Now their caps were on the ground and they were left with nothing. They do not know why one wears a cap. They simply imitate. Such imitation is not beneficial. You have to know the purpose of sadhus. You will be able to follow him by knowing the purpose.

How is association possible? Sri Rupa Goswami writes in his instructions,

dadati pratigrhnati guhyam akhyati prcchati
bhunkte bhojayate caiva sad-vidham priti-laksanam

By offering sadhu, items in accordance with their requirements, accepting remnant items given by pure devotees, revealing to devotees one's confidential realizations concerning bhajana, inquiring from them about their confidential realizations, eating with great love the prasada remnants given by devotees and lovingly feeding them prasada—these are the six symptoms of loving association with sadhu.

The other question mother Devahuti asked was, “How do I recognize a sadhu?” In response, Kapila Bhagavan first elaborated on the secondary attributes or gaun-laksana or tatastha-laksana of a sadhu. There are two kinds of characteristics of a sadhu. There is the original qualification, and when that original qualification exists, tatastha-laksana (secondary attributes) will be manifested.

titiksavah karunikah suhrdah sarva-dehinam
ajata-satravah santah sadhavah sadhu-bhusanah
(SB. 3.25.22)

Forbearance, compassion, well-wishing friendliness, no vision of foes (as sadhus see all as coming from the same source and thus inter-related), calmness, serenity, simple-heartedness.

A sadhu is tolerant and merciful. If he gets angry on silly matters, he is not a sadhu. Our Gurudev used to explain this with example. A sadhu does not have any worldly desire. If a person has any worldly desires and if those desires does not get fulfilled then that brings anger. It is said in Gita 2.62-63,

dyayato visayan pumsah sangas tesupajayate
sangat sanjayate kamah kamat krodho 'bhijayate,
krodhad bhavati sammohah, sammohat smrti-vibhramah
smrti-bhramsad buddhi-naso,buddhi-nasat pranasyati

Sadhus are devoid of any worldly desires. Sadhu's life is for the service of Supreme Lord. As he loves Him, he has love for all the jivas, in relation to Him. If I love someone then I cannot harm anything or anyone related to him. If I love someone and harm his body parts like hand or nose then it is not actual love. If we love Supreme Lord then automatically we love all the jivas who are part and parcel of Him. And we will not have mentality to harm anyone. We even cannot harm an ant; leave aside doing harm to any human being.

Our Guruji used to explain this with an example,

ghṛṣṭaṁ ghṛṣṭaṁ punar api punaś candanaṁ cāru-gandhaṁ
chinnaṁ chinnaṁ punar api punaḥ svādu caivekṣu-khaṇḍam|
dagdhaṁ dagdhaṁ punar api punaḥ kāścanaṁ kānta-varṇaṁ
prāṇānte’pi prakṛti-vikṛtir jāyate nottamānām||

(On even being rubbed again and again over a stone slab, sandalwood maintains its sweet fragrance, and so also the stem of a sugarcane plant cut again and again into small pieces retains its sweet taste. In the same manner Gold burnt and heated over fire still retains its beautiful lustre. likewise, in noble and righteous persons there is no degeneration in their high moral values even if they may be facing imminent death.)

Sandalwood, even though rubbed again and again, would never say, “You have rubbed me again and again so I will give up my nature and I will give you bad smell.” No, how much ever you rub it; it would always release a sweet fragrance. In the same manner, a sadhu would never give up his original nature, whatsoever troubles will be given to him. It could be possible with a so-called sadhu, but a bonafide sadhu will never give up his original nature. If sugacane is cut to pieces, will it say, “Oh! You have given me affliction; I shall give up my sweet nature?” If you cut it into small pieces, it will not give up its sweet taste. In the same manner if you heat gold over fire, does it ever give up its beautiful lustre and become black? No, as much you heat the gold, its glow will increase. Like this if you oppress the sadhu, his glory will be manifested ever more and more. In the holy biography of Prahlad you will find that he tolerated so many oppressions of his father and that increased his glory more and more. A sadhu cannot harm anyone.

It is very rare to find such a sadhu. A sadhu is merciful. He is compassionate towards all the living entities not only towards the human. We have heard the illustration of a sadhu saving an scorpion, repeatedly. There was one sadhu who was taking bath in a river and he saw one scorpion drowning in water. He tried to take it out but the scorpion bit him on his hand and it again got dropped. Again the sadhu tried to lift it up and again it bit him. One person was witnessing him doing so. He asked, “It is biting you repeatedly and still you are trying to save it. Why do not you let it die?” The sadhu replied, “It is its nature to bite and it is a nature of a sadhu to rescue it. If it does not leave his nature why should I do it?” So it is the nature of a sadhu to rescue the suffering jivas from their afflictions. Conditioned souls have forgotten the Supreme Lord and come to this material world so a sadhu always tries to make them inclined towards the Supreme Lord. A sadhu can stay at one place being fully absorbed in his practices, but being compassionate to the conditioned souls, he goes from one place to other place to rescue them. He cannot tolerate the tremendous sufferings of the conditioned souls of this material world. Therefore, he goes to various villages and cities to impart them the instructions, “See! You are part and parcel of Supreme Lord, you are His eternal servant. You have forgotten Him therefore you are suffering here. Take absolute shelter at His lotus feet.”

A sadhu is suhrdah sarva-dehinam — he is a real well-wisher of all living beings. It is not like that he is a friend of humans and not of animals and will cut them to pieces. He is the true friend of all living entities. It is not that he has acquired non-violence after Lord Buddha has propagated it, ma himsa sarva bhutani — do not harm any living being. By nature he loves all the living beings.

If you hurt anyone you will have to get the same suffering in return. If you slap someone, your hand will also get hurt. If you kill any living creature then you will also have to be killed by him. To every action there is equal and opposite reaction. So do not harm anyone.

A sadhu is ajata-satravah — he has no enemy. He does not consider anyone as his enemy. He sees everyone in relation with Supreme Lord. He thinks, “Nobody is responsible for my afflictions, I am reaping the fruits of my own karmas.” With such a mentality, whom could he be angry upon? No one.

māmaṅgalaṁ tāta pareṣu maṁsthā
bhuṅkte jano yat para-duḥkhadas tat
(Srimad Bhagavatam 4.8.17)

Do not blame others for your afflictions. Whatever suffering you have inflicted upon others, you will have to accept them yourself. Nobody is to be blamed. Dhruva accepted this totally and chanted the name and got the grace of Supreme Lord. Though, Dhruva did not go to anybody, by Lord's satisfaction all were satisfied. If we do not accept it then how could we get His grace? We always blame others. Every conditioned soul in this world has got defects as well as good qualities. No one is there with only qualities or only defects. But a sadhu always sees qualities in others and does not see the defects. And for an asadhu, it is the exactly opposite, he sees defects in others. If I always see defects in others then I shall be contaminated. And I shall face a spiritual fall. We should see qualities in others, however bad, a person is, he also has some good qualities.

A sadhu is santah — always peaceful. He does not have any duplicity in his heart. A duplicitous sadhu is not same as inside out.

Kapildev described the swarup laksana or original (primary) quality of a sadhu:

mayy ananyena bhavena, bhaktim kurvanti ye drdham
mat-krte tyakta-karmanas, tyakta-svajana-bandhavah

One who has one-pointed devotion unto me, is a sadhu.

om puurnnam-adah puurnnam-idam puurnnaat-purnnam-udacyate
puurnnasya puurnnam-aadaaya puurnnam-eva-avashissyate
om shaantih shaantih shaantih

Suprme Lord is purna-vastu(The infinite Supreme Lord, Unlimited). Infinite minus infinite is also infinite. Infinite never becomes zero. It is higher mathematics differential calculus. Even if innumerable conditioned souls desire to get that purna-vastu they all can get Him. There will not be any scarcity and fight amongst the 'have' and 'have-nots'. As long as we consider the physical body and limited objects of this world, land, house etc, our requirements, we cannot but quarrel with each other for acquisition of the limited objects. If a person, amongst all his family members, is dedicated fully for his family, he is considered a righteous person at that level. But if he is not doing any good to his city, then as per the city perspective, his thought process is considered to be narrow. If he is thoughtful to his city, he is not righteous for his state. Similarly, it goes to the country, to the planet etc. If he is doing good to his planet, he may be exploiting another planet. But a devotee of a Supreme Lord is dedicated to the purna-vastu, so he cannot harm anyone as nothing is outside that Unlimited. So, sadhu is one, who dedicates himself for the purna-vastu.

mayy ananyena bhavena, bhaktim kurvanti ye drdham
mat-krte tyakta-karmanas, tyakta-svajana-bandhavah

By merely abandoning varnashram dharm, one cannot become a sadhu. Incompetent persons, finding difficulty after marriage to lead household life and to maintain their family members, give up family life and may go door to door to maintain their livelihood; such a person is not called a sadhu. If one leaves the household responsibilities for the service of Supreme Lord, then it will bring eternal welfare to his wife, son and all his family members. Therefore, Kapildev says, mat-krte tyakta-karmanas, tyakta-svajana-bandhavah — if he leaves the family responsibilities for the service of the Supreme Lord then only it will be beneficial. Supreme Lord Sri Krishna also has instructed in Gita,

sarva dharman parityajya mamekam saranam vraja
aham tvam sarvapapebhyoh moksayisyami ma suchah
(BG 16.6)

Abandon all your all responsibilities and take absolute shelter unto Me, I will free you from all sins. You need not worry about it or have any fear. Kapildev also has said:

mad-asrayah katha mristah srinvanti kathaynti cha
(SB. 3.25.23)

(A sadhu is always engaged in listening and singing the glories of Me)

There are many professional speakers, who speak for money. But one should speak harikatha for the satisfaction of Supreme Lord only. There was one Brahmachari in Chandigarh math, who is a sanyyasi now. One day one Mataji approached him saying, “One well-known Bhagavat speaker has come to the city. You should go to listen to his discourses. ”

The Brahmachari replied, “I am serving here in the math, if I will get time, I will go.”

He did not go that day.

Next day again, that Mataji told him, “He will not stay here for a long, you should go there and listen from him.”

He replied, “I will try.” But he did not go.

The next day, Mataji again asked him, “Did not you go?”

That Brahmachari asked her, “Why do you think that by listening to him, I will get benefited?”

She replied, “I think so because he is charging ten thousand rupees to listen to him.”

On hearing so, the Brahmachari replied, “I need not go there to listen to such a speaker.”

If you speak with the intention of earning money then it is not Harikatha or Bhagavad-katha. If you speak for the satisfaction of the Supreme Lord then only it is Bhagavad-katha. It is not so easy. Means are justified by the ends. When end is good everything is good and vice versa.

One can say, a sadhu also becomes ill. But it is not so, externally he may show some illness, but internally his mind is continuously absorbed in the Supreme Lord.

tapanti vividhas tapa, naitan mad-gata-cetasah
(SB. 3.25.23)

(The sadhus do not suffer from material miseries because they are always filled with thoughts of My pastimes and activities.)

One experiences happiness or distress through his mind. Externally, he may shout, 'aah', 'uhh', but internally his mind is always absorbed in Supreme Lord. Our Gurudev used explain us in this regard, “Conditioned souls cannot get their eternal welfare without serving a sadhu. But a sadhu never engages anybody in his service considering himself a sadhu. And therefore, Supreme Lord makes some arrangement by which the conditioned soul can serve a sadhu. He gives so called illness to sadhu. He makes the sadhu in need of help so that jiva can serve him.” Externally, he shows some illness but internally he is always absorbed in the thoughts of Supreme Lord. By associating with such a sadhu, all our bad qualities and anarths (unwanted things), acquired by bad association, will go away.