Those who have attained everlasting life in the vision of God doubtless know very well that it is no mere bribe, but the very consummation of their earthly discipleship; but we who have not yet attained it cannot know this in the same way, and cannot even begin to know it at all except by continuing to obey and finding the first reward of our obedience in our increasing power to desire the ultimate reward. Just in proportion as the desire grows, our fear lest it should be a mercenary desire will die away and finally be recongized as an absurdity. But probably this will not, for most of us, happen in a day; poetry replaces grammar, gospel replaces law, longing transforms obedience, as gradually as the tide lifts a grounded ship. – C. S. Lewis, The Weight of Glory