Read "What Men Live By" by Leo Tolstoy. (Thanks Yoonhee for the recommendation. :) )
And God said: 'Go... and learn three truths: Learn
What dwells in man,
What is not given to man, and
What men live by.
"I knew before that God gave life to men and desires that they
should live; now I understood more than that.
"I understood that God does not wish men to live apart, and
therefore he does not reveal to them what each one needs for
himself; but he wishes them to live united, and therefore reveals to
each of them what is necessary for all.
"I have now understood that though it seems to men that they live by
care for themselves, in truth it is love alone by which they live.
He who has love, is in God, and God is in him, for God is love."