You know, I've always seen that verse as something like 'I'm the only way you folks can have atonement and get to heaven. Zoroaster and Bhudda were really cool guys but they're not going to be the ones to suffer and die, destroy the gates of hell, free everybody, kick Satan's ass and defeat the powers of death and evil three days later.'

As an analogy, I would be sort of like saying 'Sherlock Holmes is the way, the truth and the life. Edgar Allan Poe wrote really good mystery stories before, but nobody can write proper detective fiction without reading Hound of the Baskerviles.' Or, perhaps, 'Snow White and the Seven Dwarfs is the way, the truth and the life. There were plenty of great cartoon shorts before, but nobody knew that full length animated features were a good idea except through it.'

Okay, sorry, I'm a nerd. But you get my point.

As for unbelievers, Jesus says 'I have other sheep that do not belong to this fold' in John. Paul also says that the law is automatically written on Gentiles's hearts and that God judges according to the secret thoughts of all. Saint John says that 'Everyone who loves has been born of God and knows God'. I have a pretty strong feeling that moral and compassionate nonbelievers have experience God in some form or the other-they just don't know what they've experienced. I think they'll have a pretty nice surprise after they die.