Here is what I was told in PSR. Jesus existed, and he taught with himself as the son of God. This gives us three options. He was telling the truth, he was a liar, or he was crazy. If he was crazy, how can We accept his teachings in the manner of Aristotle as you suggest? His teachings could have been just as crazy as him. If he was a liar, than he was not a great man or teacher as you suggest. In my eyes, this leaves truth as the only option. This is my opinion. He cannot be a good man or good teacher when he saw himself as the son of God and taught so, if he was a liar or nuts.