Man can enter spiritual life and inhale spiritual air only if he feels that without spiritual life he is dead, the way the body dies when life leaves it, and that he ardently wishes to live.
But by which means can man rise to such a level that complete elimination of all self-interest and concern for himself and a yearning to give all of himself will become the only goal of his life, to the extent that, without achieving this goal he will feel as if he were dead? Rising to this level takes place gradually and is based on the principle of counteraction: the more efforts man makes in his quest for a spiritual road, in study, in his attempts to artificially imitate spiritual objects, the more convinced he becomes that he is unable to attain it by himself.
Courtesy of http://www.youtube.com/watch?v=x5RFActfKRQ