Faith and Actions

Christians have often disputed as to whether what leads the Christian home is good actions, or Faith in Christ. I have no right really to speak on such a difficult question, but it does seem to me like asking which blade in a pair of scissors is most necessary. A serious moral effort is the only thing that will bring you to the point where you throw up the sponge. Faith in Christ is the only thing to save you from despair at that point: and out of that Faith in Him good actions must inevitably come.  There are two parodies of the truth which different sets of Christians have, in the past, been accused by other Christians of believing: perhaps they may make the truth clearer. One set were accused of saying, ‘Good actions are all that matters. The best good action is charity. The best kind of charity is giving money. The best thing to give money to is the Church. So hand us over £10,000 and we will see you through.’ The answer to that nonsense, of course, would be that good actions done for that motive, done with the idea that Heaven can be bought, would not be good actions at all, but only commercial speculations. The other set were accused of saying, ‘Faith is all that matters. Consequently, if you have faith, it doesn’t matter what you do. Sin away, my lad, and have a good time and Christ will see that it makes no difference in the end.’ The answer to that nonsense is that, if what you call your ‘faith’ in Christ does not involve taking the slightest notice of what He says, then it is not Faith at all—not faith or trust in Him, but only intellectual acceptance of some theory about Him.
The Bible really seems to clinch the matter when it puts the two things together into one amazing sentence. The first half is, ‘Work out your own salvation with fear and trembling’— which looks as if everything depended on us and our good actions: but the second half goes on, ‘For it is God who worketh in you’—which looks as if God did everything and we nothing. I am afraid that is the sort of thing we come up against in Christianity. I am puzzled, but I am not surprised.   You see, we are now trying to understand, and to separate into water-tight compartments, what exactly God does and what man does when God and man are working together. And, of course, we begin by thinking it is like two men working together, so that you could say, ‘He did this bit and I did that.’ But this way of thinking breaks down. God is not like that. He is inside you as well as outside: even if we could understand who did what, I do not think human language could properly express it. In the attempt to express it different Churches say different things. But you will find that even those who insist most strongly on the importance of good actions tell you you need Faith; and even those who insist most strongly on Faith tell you to do good actions. At any rate that is as far as I can go.
C.S. Lewis, Mere Christianity (1952; Harper Collins 2001) 148-149.