C. S. Lewis (1898-1963), Oxford professor, author across literary genres, and Calvinist in cognito (even to himself), writes this on the fundamental change that must happen if we are to be truly morally motivated:
"But what man, in his natural condition, has not got, is Spiritual life—the higher and different sort of life that exists in God. We use the same word life for both: but if you thought that both must therefore be the same sort of thing, that would be like thinking that the 'greatness' of space and the 'greatness' of God were the same sort of greatness. In reality, the difference between Biological life and spiritual life is so important that I am going to give them two distinct names. The Biological sort which comes to us through Nature, and which (like everything else in Nature) is always tending to run down and decay so that it can only be kept up by incessant subsidies from Nature in the form of air, water, food, etc., is Bios. The Spiritual life which is in God from all eternity, and which made the whole natural universe, is Zoe. Bios has, to be sure, a certain shadowy or symbolic resemblance to Zoe: but only the sort of resemblance there is between a photo and a place, or a statue and a man. A man who changed from having Bios to having Zoe would have gone through as big a change as a statue which changed from being a carved stone to being a real man.
"And that is precisely what Christianity is about. This world is a great sculptor’s shop. We are the statues and there is a rumor going round the shop that some of us are some day going to come to life."
--Mere Christianity, 139-140
"I can to some extent control my acts: I have no direct control over my temperament. And if (as I said before) what we are matters even more than what we do—if indeed, what we do matters chiefly as evidence of what we are—then it follows that the change which I most need to undergo is a change that my own direct, voluntary efforts cannot bring about. And that applies to my good actions too. How many of them were done for the right motive? How many for fear of public opinion, or a desire to show off? How many from a sort of obstinacy or sense of superiority which, in different circumstances, might equally have led to some very bad act? But I cannot, by direct moral effort, give myself new motives. After the first few steps in the Christian life we realize that everything which really needs to be done in our souls can be done only by God."
"There are three kinds of people in the world. The first class is of those who live simply for their own sake and pleasure, regarding Man and Nature as so much raw material to be cut up into whatever shape may serve them. In the second class are those who acknowledge some other claim upon them – the will of God, the categorical imperative, or the good of society – and honestly try to pursue their own interests no further than this claim will allow. They try to surrender to the higher claim as much as it demands, like men paying a tax, but hope, like other taxpayers, that what is left over will be enough for them to live on (this idea is also in Mere Xianity). Their life is divided, like a soldier’s or a schoolboy’s life, into time 'on parade' and 'off parade', 'in school' and 'out of school'. But the third class is of those who can say like St Paul that for them 'to live is Christ'. These people have got rid of the tiresome business of adjusting the rival claims of Self and God by the simple expedient of rejecting the claims of Self altogether. The old egoistic will has been turned round, reconditioned, and made into a new thing. The will of Christ no longer limits theirs; it is theirs. All their time, in belonging to Him, belongs also to them, for they are His.
"The price of Christ is something, in a way, much easier than moral effort – it is to want Him."
"Three Kinds of Men," in Present Concerns, 21-22
For sites devoted to Lewis see the C. S. Lewis Institute, Into the Wardrobe, and the C. S. Lewis Foundation.