A classic Christian argument for the divinity of Jesus Christ is called the Lord, Liar or Lunatic argument. This position was probably best explained by Christian author C. S. Lewis. He presented the argument twice: once in a stronger form in the middle of a children’s story and another time in a purely Christian context, though in a weaker form. The argument is summed up like this: Jesus claimed to be the son of God. Because he made these claims, he must either be lying or telling the truth (or completely crazy). But we will show there is no reason to believe he is any of these things. Setting up a logically flawed argument does not a proof make.
The Lucy Argument
In the first Narnia book (The Lion, the Witch and the Wardrobe) young Lucy stumbles across a gateway to another land inside of magical wardrobe. When she tells the other children about the fantasy land, they are quick to doubt her. But when the children approach the professor (their caregiver) about the wardrobe, he defends Lucy. Surely she must be either lying, crazy or telling the truth. Since she is not crazy and is not someone with a history of telling lies, it seems likely she is telling the truth.
Says the Professor, “There are only three possibilities. Either your sister is telling lies, or she is mad, or she is telling the truth. You know she doesn’t tell lies, and it is obvious that she is not mad. For the moment then and unless any further evidence turns up, we must assume that she is telling the truth.” Sounds pretty simple.
If this logic were correct, then Lucy most likely was telling he truth (which incidentally she was). Without being a liar or lunatic she is left only to be an honest girl. And in this context, these seem to be the only real options. She could be telling stories or joking, but that can be categorized as a lie. The only way out was that she was seeing things, which would be highly unlikely in this case where she was seeing the same fantastic elements for well over an hour and engaging in conversation with them.
The Christ Argument
In his book of wartime addresses, Mere Christianity, Lewis tries the same argument for Jesus Christ being the son of God. Jesus claimed to be the son of God; if not known for lying and clearly not mad, he must be telling the truth, right? As Lewis says, “Either this man (Jesus) was, and is, the son of God, or else a madman or something worse.” Also, “You can shut Him up for a fool, you can spit at Him and kill Him as a demon, or you can fall at his feet and call Him Lord and God.”
Under the same logic used for Lucy, this seems to be true. Christ was not known for lying. He certainly did not appear to be crazy. And to think he was just seeing things is a bit of a stretch. While many people probably falsely believe they have spoken with God, Jesus could not have been mistaken to be God’s only son. Could he? 
But What of Third-Person Stories?
Suppose I say that President Bush said he had the power to leap tall buildings in a single bound. Well, Bush must either be completely crazy or a liar or have some incredible superpowers, right? According to the logic used by Lewis, we’d have to conclude this. Our instinct would be to assume Bush is a liar, as he is known for having a history of lies. But we are overlooking an important part of this argument: Did Bush tell you he had these powers, or did you merely hear me tell you he said this?
And this is the same case with Jesus claiming to be God. Did Jesus ever make this claim to you, or did you only hear someone else tell you he made this claim? You heard it secondhand, didn’t you? And actually you didn’t even hear the statement secondhand – you heard it third or fourth hand, because the man you heard it from never spoke with Jesus either. What does this tell us? Maybe Jesus is the son of God, and maybe he is not. Another person telling you he said something is no more authoritative than me telling you wild stories about President Bush. You cannot logically deduce anything from the statements made on behalf of another.
The Literal and the Poetic
Jim Perry points out that even if Jesus were quoted completely accurately, this still would not automatically mean that he claimed to be God. In fact, such a clear and concise statement as “I am the only begotten son of the Father” is never stated. When he says that “I and the Father are one”, this does not have to be seen as saying that they are the same entity. This simply means they are united – in spirit or in purpose. A team is “one” but this does not mean all the people on the team share one flesh, but rather a goal.
Jesus was known for his parables and wordplay. When he said that it was easier for a camel to pass through the eye of a needle than for a rich man to enter Heaven, there certainly must be some wiggle-room to this statement. The very idea of a camel doing what was suggested is more imagery than possibility.
The Case for Mohammed
Christians may appreciate the trilemma as a way to comfort themselves that Jesus was, indeed, the son of God. But they seem less likely to accept this same logic when used for other religions. Muslims believe Mohammed was the prophet of God (Allah). Mohammed claimed this. He was not crazy and he cannot be proved to be a liar (certainly his followers would never think this). So he must be the prophet, right? All the Christians who use the trilemma to accept Jesus as Lord would have to accept Mohammed as a prophet by the same standards.
In fact, Mohammed’s case is possibly stronger than Jesus’ due to the direct writings of Mohammed being around rather than the secondhand accounts of his followers. In other words, if we believe Lucy we should believe Mohammed.
But What About Joseph Smith or L. Ron Hubbard?
And the lesser religions (or “less mainstream”) must be true, too. Joseph Smith was not crazy and his supporters (the Mormons) would not consider him a liar . Jesus must really have appeared before the Indians in America. And Smith must really have found golden tablets written in a language only he could decipher and then lost the tablets before anyone could see them.
L. Ron Hubbard ,the founder of Scientology was also neither crazy or a liar. So his religion that claims alien souls are on earth and that an evil alien named Xenu exists must be a fact. Would such stars as John Travolta, Tom Cruise and Kirstie Alley really invest so much time and money into the faith if it was not based on solid fact? 
Was Jesus the son of God? Maybe, maybe not. We might be able to prove his divinity somehow, but this method is not reliable in the least. Such methods as historical study or faith might be acceptable. What we must really wonder is how serious Lewis took this idea. He used it twice, implying that he thought it was convincing. Yet, he was educated in philosophy and such a flawed argument should never have been accepted by him. We will never know.
 Compare this to Charles Manson or David Koresh. Manson and Koresh were not known to be liars and could put up an appearance of sanity. Both could maintain meaningful relationships with other people, especially women. But a closer examination of their psyches reveals that they were not mentally stable by society’s definition. Their claims to be gods are undermined by this mental illness. Although one also wonders if a deity were to appear in the form of a man in this age if they could live their life without being branded insane by society.
 As a non-Mormon, I think the evidence strongly suggests that Smith was a conman and deceived his followers. But you cannot convince them of this.
 As a non-Scientologist, my personal opinion is that L. Ron Hubbard never meant to create a religion but was simply working in the fantasy world (he was, after all, a science fiction author). Somewhere along the way a follower of Hubbard’s transformed these ideas into a master religion. Hubbard’s Scientology books, with the alien parts omitted, actually make a fair amount of sense.
Howard-Snyder, Daniel. “Was Jesus Mad, Bad, or God?… Or Merely Mistaken?” http://www.cc.wwu.edu/~howardd/mbgfp5web.pdf. Viewed December 14, 2005.
Lewis, C. S. The Lion, the Witch and the Wardrobe.
Lewis, C. S. Mere Christianity.
Perry, Jim. “The Trilemma — Lord, Liar or Luantic?” 1995. http://www.infidels.org/library/modern/jim_perry/trilemma.shtml
“Trilemma”, Wikipedia. http://en.wikipedia.org/wiki/Trilemma Viewed December 14, 2005.