Eating the Food the Universe Grows

"We are bidden to "put on Christ," to become like God. That is, whether we like it or not, God intends to give us what we need, not what we now think we want. Once more, we are embarrassed by the intolerable compliment, by too much love, not too little.  Yet perhaps even this view falls short of the truth. It is not simply that God has arbitrarily made us such that He is our only good. Rather God is the only good of all creatures: and by necessity, each must find its good in that kind and degree of the fruition of God which is proper to its nature. The kind and degree may vary with the creature's nature: but that there ever could be any other good, is an atheistic dream. George MacDonald, in a passage I cannot now find, represents God as saying to men "You must be strong with my strength and blessed with my blessedness, for I have no other to give you." That is the conclusion of the whole matter. God gives what He has, not what He has not: He gives the happiness there is, not the happiness that is not. To be God—to be like God and to share His goodness in creaturely response—to be miserable—these are the only three alternatives. If we will not learn to eat the only food that the universe grows—the only food that any possible universe ever can grow—then we must starve eternally." 

—C.S. Lewis, The Problem of Pain: Divine Goodness