Truth never shares its pedestal.
Jesus said, "I am the Way, the Truth, and the Life. No one comes to the Father except through me."
Simple logic. Jesus was one of three people. First we could suppose him a liar, bent on the worst evil and deceiving the world. He built a deception in his whole life that would unalterably change the world to accomadate a lie.
Don't like this Jesus? Good, because neither do I. Second, we could suppose Jesus to be crazy, a maniacal man bent on his destruction and the destruction of his people. He did what he did out of some mental disease and was unable to help himself. Indeed, not only did he end on the cross, he has followers by the thousands who have irrationally followed his madness.
I don't think that works too well either. Third we have the Jesus who was who he said he was. The Son of God come to redeem a lost world. As Lewis so aptly points out we are not ever, in strict logic, left with the idea that Jesus is merely a nice man.
Would that the world was better trained in simple logic! What do they teach them in schools these days? (Oops, that would be me!)