Here is a famous passage from C. S. Lewis' Mere Christianity:
I am trying here to prevent anyone saying the really foolish thing that people often say about Him: 'I'm ready to accept Jesus as a great moral teacher, but I don't accept His claim to be God.' That is one thing we must not say. A man who was merely a man and said the sort of thing Jesus said would not be a great moral teacher. He would either be a lunatic — on a level with the man who says he is a poached egg — or else he would be the Devil of Hell. You must make your choice. Either this man was, and is, the Son of God: or else a madman or something worse. 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. But let us not come with any patronizing nonsense about His being a great human teacher. He has not left that open to us. He did not intend to.
This passage sets forth the famous Lewis Trilemma: Jesus is either the Son of God, or he is a lunatic, or he is the devil. This trilemma is also sometimes put as a three-way choice between lord, lunatic, or liar.
First, a terminological quibble. A dilemma, strictly speaking, is not just any old problem, but a problem with exactly two alternatives, both of which are unacceptable. Thus talk of being impaled on the horns of a dilemma. Use the word in any other way, and you are misusing it. A trilemma simply adds a third unacceptable 'horn.' Now since it is not unacceptable to Lewis and to Christians that Jesus be lord, the name 'Lewis Trilemma' is a misnomer. An example of a trilemma in the strict sense would be the situation in which a Muslim jihadi says to the ‘infidel’: either convert to Islam, accept dhimmitude, or be put to the sword. My pedantry now having been satisfied, I proceed to a substantive point.
Without having examined this issue with the care it deserves, and laying myself open to a thrashing by Biblical exegetes, why isn't it possible that Jesus was exaggerating or speaking in some other extended or figurative way? To exaggerate is not to lie, nor is it to give evidence of mental instability. Serious people sometimes exaggerate to make serious points. I once heard a medical doctor state on a radio show that one's cholesterol level cannot be too low. That is a wild exaggeration, but in the context it was used to express the reasonable proposition that most of us have cholesterol levels that ought to be reduced somewhat.
When Jesus says, "I and the Father are one," for example, this could be taken as an exaggerated expression of the proposition that Jesus and the Father are on extremely intimate, or even uniquely intimate, terms, that Jesus is the recipient of mystical graces that he would share with his followers if only they would accept him as standing in this most intimate relation with the Father. Or something along these lines. On this reading, Jesus is not saying that he is literally identical to God, but that he is 'one' with God in perhaps a sense not too different from the sense in which one person is 'one' with another whom he or she deeply loves. One could say as Jesus does at Matthew 19:5 that man and wife are 'one flesh' without meaning that they are Siamese twins or that they are literally one and the same.
That this is a possible interpretation show that the notion that there are exactly three possibilities is dubious. Let us be clear that the question before us is solely whether there is good reason to think that the three-way disjunction, lord or lunatic or liar, is logically exhaustive.
A fifth possibility is that Jesus intended his assertions mystically. "The kingdom of heaven is within you" invites a mystical reading: the kingdom of heaven is not a material kingdom, a land of milk and honey, lying in the future and to be attained by political action and a 'smiting' of enemies. The kingdom of heaven is rather to be achieved here and now via an inner path, by an alteration of one's ordinary ego-obsessed consciousness, a plunging beneath the level of ordinary egoic consciousness to a level at which the individual soul becomes capable of experiencing God, not a god of a particular tribe who will smite the enemies of that particular tribe, but a God of all, a God accessible to all via a path involving moral purification and spiritual exercises. The saying that "I and the Father are one" could then be interpreted as meaning that Jesus has achieved this alteration of ordinary consciousness, that he has realized (in the two-fold sense of having made real and having taken cognizance of) his sonship with God. His message would then be: I have achieved this realization, and you can too. I have been there and I will help you get there. I am a son of God and perhaps the only son of God so far, but you too can become sons and daughters of God in the same sense as I am.
This of course flies in the face of orthodoxy, but recall that the issue is whether the three-pronged disjunction is exhaustive. For if it is not exhaustive, then one cannot infer that Jesus is literally God from the the two facts that he is not a lunatic and not a liar. Suppose there are four prongs: lord, lunatic, liar, mystic. One can still argue that Jesus is the unique son of God, but now three alternatives need to be eliminated and not just two. If that is right, then what we have is not a 'trilemma' but a 'tetralemma.' Let us conclude by examining how Peter Kreeft excludes the mystic alternative.
Kreeft thinks the 'trilemma' is "logically airtight," that "there is simply no way out." There are only three options, lord, liar or lunatic, and the second two can be excluded. And indeed they can. But if there are only three options, why does Kreeft discuss the mystic option? He takes it seriously enough to rebut it, which shows that he considers it a fourth option. Kreeft puts the mystic option as follows:
The second escape . . . is to Orientalize Jesus, to interpret him not as the unique God-man but as one of many mystics or “adepts” who realized his own inner divinity just as a typical Hindu mystic does. This theory takes the teeth out of his claim to divinity, for he only realized that everyone is divine. The problem with that theory is simply that Jesus was not a Hindu but a Jew! When he said “God”, neither he nor his hearers meant Brahman, the impersonal, pantheistic, immanent all; he meant Yahweh, the personal, theistic, transcendent Creator. It is utterly unhistorical to see Jesus as a mystic, a Jewish guru. He taught prayer, not meditation. His God is a person, not a pudding. He said he was God but not that everyone was. He taught sin and forgiveness, as no guru does. He said nothing about the “illusion” of individuality, as the mystics do.
This is a cheap polemic that could convince only someone who needs no convincing. First of all, a mystic need not be a Hindu; there are mystics in all religious traditions. There are even Jewish mystics. Pointing out that Jesus was a Jew does nothing to show that he was not a mystic. He might have been a Jewish mystic. Second, a mystic need not envisage the ultimate as impersonal, as a "pudding," as Kreeft deprecatingly puts it. That's a cheap-shot; as cheap as when a Muslim describes the Trinity as the doctrine that there are three gods. A mystic might hold that there is a personal God, and that he is transcendent, but also hold that mystical experience of God is possible for all in which case all are potentially sons and daughters of God. Third, the opposing of prayer and meditation is shallow; prayer in its higher reaches becomes meditation as Augustine and Aquinas maintain.
My point is very simple. It is not that one cannot argue against all competitors to the claim that Jesus is the unique God-Man. One can. My point is that there are more than two competitors, and that they cannot be dismissed out of hand in the way the ‘liar’ and ‘lunatic’ can. The 'trilemma,' then, may convince people, but it ought not; it has no probative force. People like Kreeft inadvertently concede as much when they discuss the further possibilities that Jesus never claimed to be divine and that he might have meant his characteristic sayings mystically.
The Lewis ‘Trilemma’ does not prove the divinity of Jesus. It does however have the merit of raising the question of the divinity of Jesus in a concrete way and helping people to take it seriously. The sayings attributed to Jesus clearly do not have their origin in lunacy or demonic mendacity. He speaks with an unearthly authority, an authority that would be explained if he is indeed and uniquely God Incarnate. Could he be?