Srila Param Gurudev explains the difference between namabhas, namapradha and pure names of the Supreme Lord. A house holder can also be a sadguru. One should accept the holy name only from the mouth of a Ananya bhakt. Later by giving example of Prahlad Maharaj he establishes that Lord is always merciful to His devotees, bhakta vatsal. One who does not believe in the eternal existence of Lord cannot give us the Lord.