Lewis here talks about the last, but by no means the least, of the theological virtues: faith.
He defines faith as trust in God. He explains that faith and reason don’t contradict each other, they go together. Or rather, one is the foundation of the other — Christian faith is based on reason. The battle, he argues, is not between faith and reason, but faith and reason on the one hand, and emotions and imagination on the other. What can “shake” a person’s faith is not reason — usually, it’s his changing moods.
Lewis thinks that, since our moods are unpredictable and can significantly affect our beliefs, we must therefore strengthen our faith by practicing it regularly: through prayer, reading and studying Scripture, going to church, receiving the sacraments, and so on. That’s why faith is really a virtue.
I love this quote:
“I am not asking anyone to accept Christianity if his best reasoning tells him that the weight of the evidence is against it. That is not the point at which Faith comes in. But supposing a man’s reason once decides that the weight of the evidence is for it. I can tell that man what is going to happen to him in the next few weeks. There will come a moment when there is bad news, or he is in trouble, or is living among a lot of other people who do not believe it, and all at once his emotions will rise up and carry out a blitz on his belief. Or else there will come a moment when he wants a woman, or wants to tell a lie, or feels very pleased with himself, or sees a chance of making a little money in some way that is not perfectly fair: some moment, in fact, at which it would be very convenient if Christianity were not true. And once again his wishes and desires will carry out a blitz. I am not talking of moments at which any real new reasons against Christianity turn up. Those have to be faced and that is a different matter. I am talking about moments when a mere mood rises up against it.”
“Faith… is the art of holding on to things your reason has once accepted, in spite of your changing moods.”
I totally agree with him. Faith and reason are not mutually exclusive. They work together. Or, as Pope John Paul II said,
“Faith and reason are like two wings on which the human spirit rises to the contemplation of truth; and God has placed in the human heart a desire to know the truth – in a word, to know himself – so that, by knowing and loving God, men and women may also come to the fullness of truth about themselves.”
Or, as Christian author Sean McDowell said,
“Faith is trusting something which we have reasons to believe is true.”
So, belief in God is actually reasonable. It is not “blind”.