did c.s. lewis lose a debate and also his faith. I want to read mere Christianity but i

[James]

have a question first? i heard that he lost a debate (to an atheist) and ended up changing a part of one of his books, i think it was Miracles. Some people say that because of this, he stop writing books on theism and started writing books like Narnia. How true is this, i would like to read Mere Christianity but if he stopped believing at some point in his life, i'm wondering if i should read it. Thanks,