William Marshall

“Now we cannot...discover our failure to keep God's law except by trying our very hardest (and then failing). Unless we really try, whatever we say there will always be at the back of our minds the idea that if we try harder next time we shall succeed in being completely good. Thus, in one sense, the road back to God is a road of moral effort, of trying harder and harder. But in another sense it is not trying that is ever going to bring us home. All this trying leads up to the vital moment at which you turn to God and say, "You must do this. I can't.”
― C.S. Lewis

“To have Faith in Christ means, of course, trying to do all that He says. There would be no sense in saying you trusted a person if you would not take his advice. Thus if you have really handed yourself over to Him, it must follow that you are trying to obey Him. But trying in a new way, a less worried way. Not doing these things in order to be saved, but because He has begun to save you already. Not hoping to get to Heaven as a reward for your actions, but inevitably wanting to act in a certain way because a first faint gleam of Heaven is already inside you.”
― C.S. Lewis, Mere Christianity