Are you some kind of Unitarian or something?
As the guy was arguing last night: either you believe Jesus was the son of god or you don't. If you do believe that, you must also believe that those who do not believe it are wrong. You must believe that you have an important knowledge of the truth that they are lacking. We see nuance and variation within a given sect, but whether you are a Tibetan Buddhist or an Evangelical Christian, there are certain core beliefs that you have accept as "true," no? (I could be wrong, as I never went to divinity school, but I think that is how it works.)
Jesus does not refer to Himself in the Bible as the Son of God, but as the Son of Man.
And no, one who believes this does not have to believe others to be wrong about their beliefs. That's where the handy, "I don't know the ways and intentions of God" comes in handy. I do believe in Christ, but I don't believe that God necessarily came to everyone in the same guise. This isn't much of a stretch, is it? I mean, if someone is willing to believe that a person was raised from the dead and asked others to eat of His flesh, is it really that much harder to believe that maybe God sent Buddha to some folks and Shiva to others?