There is nothing that prevents somebody who has a few crazy ideas about himself to be a great moral teacher in other respects. The one simply hasn’t got anything to do with the other.
Besides, Jesus was not a ‘great’ moral teacher. He was not an utterly bad moral teacher either, but his morality was lacking too much to be called ‘great’.
I certainly don’t think somebody who didn’t consider slavery wrong to be a great moral teacher. As a human being living in the first century his moral stance of slavery may be somewhat excusable, as the Son of God, it imost certainly isn’t. And that’s just one example. His completely unjustified rage at people doing their jobs in the temple is another one.
You appear to have misunderstood the simple logic of Lewis’s statement. Crazy is only crazy. Just because crazy happens to speak some universally true thing does not make him less crazy. In fact, because so many, “Great,” men (and women) in history have stated nearly exactly the same basic moral teachings as Christ did, AND WERE SANE, one might just as well discard him entirely and simply follow them. The Christian does not try to follow Jesus’s path because he said some really great things. As I said, many have said great, true things. We follow him because he is the Christ, the Son of the living God. He is God. You don’t have to believe that. But, please, don’t condense what we believe into something contrary to what he said (like condoning slavery? Wher’d you pull that from Sacred Scripture?). I promise not to condense your god, which for an atheist must necessarily be himself, into anything you aren’t teaching. One last thing, if I’m right about who Jesus is (not was), your statement about his chastising, “People doing their jobs in the temple,” is ludicrous. What he did is the same thing as you tossing people out of your house for defacing it. He is God, in that tract from Matthew. Therefore, we see the temple as his. You’re still picturing him as merely a teacher. We don’t see him as such. Therefore your use of that, “Example,” won’t work on a believer BECAUSE we see it as his house.
Look brother (sister?), you can be an atheist if you want to be. That’s your free choice by the grace of God. But, if that’s your decision, you might want to consider why you are here on this forum (also your free choice). I mean, if you’re so committed to atheism, why are you trying to evangelize here?
If you want to learn about we Christians, and Christian Catholics in particular, I humbly suggest you open your mind to the possibility we are right (I investigated your creed for most of my life). At the very least, learn what we believe and accept the very real truth of it. We don’t just believe it. We know God is. We know Christ is God and the consubstantial, co-eternal, only Son of the Father. Again, you don’t have to believe it. I pray that you do one day, but, your choice. However, if you wish to engage us in clean conversation and discussion, you should try to know what we, “Know.”