In the Bhagavad-gita, Eighteenth Chapter, the Lord states that one who is engaged in preaching Krsna consciousness is very dear to Him. A preacher has to face many difficulties in his struggle to preach pure Krsna consciousness. Sometimes he has to suffer bodily injuries, and sometimes he has to meet death also. All this is taken as a great austerity on behalf of Krsna. Krsna therefore has said that such a preacher is very, very dear to Him. If Krsna's enemies can expect salvation simply by concentrating their minds on Him, then what to speak of persons who are so dear to Krsna? The conclusion should be that the salvation of those who are engaged in preaching Krsna consciousness in the world is guaranteed in all circumstances. But such preachers never care for salvation, because factually one who is engaged in Krsna consciousness, devotional service, has already achieved salvation.

From Srila Prabhupada's Krsna Book