Krsna consciousness means to become absorbed in serving the Supreme Lord and His name, qualities, form, pastimes, etc. In other words, it means becoming an instrument for His satisfaction. We have to become infused with His spiritual potency; thus strengthened, we then have to make the propagation of His transcendental glories our prime duty in life. By means of such potent missionary activities, innumerable jivas can experience endless spiritual joy.

(From "Renunciation Through Wisdom" by Srila Prabhupada)