From a Christian viewpoint, though, the message is indeed not as important as what Jesus was supposed to have done. If Jesus was a philosopher, his message might have been independent of his life. But if what's important about Jesus isn't his set of teachings, but his sacrificial death which enables us to be adopted children of God, Jesus had to be real to perform that task. Paul said the Christian faith is vain if Jesus didn't rise from the dead.

So I think you're talking about a perspective on Christianity that implicitly counts against Christian faith.