One of the most interesting points I find in C.S. Lewis’ Mere Christianity is not even found in the body of the book, but the preface. Here he defines what “mere” Christianity is (Although I have heard the book title many times, I have never known what it meant.): he explains that sometimes it is advantageous to look at Christianity not as numerous denominations holding many doctrinal standards, but merely as Christianity in general. This is what Lewis does in Mere Christianity. As a Christian apologist, Lewis undertook the difficult task of evaluating, even arguing, Christianity from an outside perspective. He looked at it instead of along it, to use his terminology. I agree with Lewis when he says “Our divisions should never be discussed except in the presence of those who have already come to believe that there is one God and that Jesus Christ is His only Son.” After all, if we are witnessing to those who do not believe, they wouldn’t have very much desire to know God if they see us arguing points that relate to matters less than “mere” Christianity. For example, fighting with someone about eschatological interpretations of Revelation would just confuse a non-Christian and make him think Christianity is divisive and offers no real Truth; it just causes more problems.
Another interesting point Lewis brings up in the preface is the definition of the word “Christian”. Apparently some of his contemporaries objected to him trying to identify what a Christian was, as if he were judging people. “May not many a man who cannot believe these doctrines be far more truly a Christian, far closer to the spirit of Christ, than some who do?” asked his critics. To explain this, Lewis tells us the history of the word “gentleman,” and how it used to simply mean someone who had a coat of arms and owned land. Over time, it traded in its factual meaning for a “deeper” one, and now means someone who acts how the gentlemen of old were supposed to act. As Lewis says, if people are allowed to start deepening the meaning of the word “Christian,” it will cease to be related to the Bible; Christian will be synonymous with “good person” or “gentleman”. In fact, it is significantly more judgmental to call someone a good person than it is to call someone a Christian, meaning someone who believes “that there is one God and that Jesus Christ is His only Son.”
One final point that I really like that Lewis makes is found in chapter one. He tells us that there is a Natural Law, a standard of behavior, for mankind. The best proof I found of this in the text in when Lewis talks about making excuses. If there were no standard, we would not attempt to give reasons why our actions are justified, why they comply with the standard.