That is inherent in the very root of Christianity.
Christians believe Jesus is the Savior of man. If other groups, such as the Jews, can achieve salvation without His intercession, then this claim is false.
Jesus himself said, "Nobody comes to the Father except through me." No exceptions, even for His relatives.
If you reject that statement, you can still believe He is a great moral teacher, but you can't believe He is the Messiah in any meaningful sense.
Perhaps you can answer a question for me that I have wondered about for quite some time. Many Jews are apparently seriously offended by (what they believe to be) the Christian belief that Jews who don't accept Jesus as their Savior will go to hell. This pops up every so often when some Jewish group gets its panties all wadded up of the Southern Baptists or some other group.
I find this very odd. Quite a few Christians who believe differently from me on various aspects believe that I will therefore go to hell. This doesn't bother me at all, since their belief will presumably not affect God's judgment in any way.
Either they are right, and I'm in for eternity in the toaster, or they're wrong and I'm not. Either way, why should I (or the Jews I mentioned) care one way or another what some random idiot believes?
Obviously such belief can for fanatics lead to regrettable actions in the real world. But I think it has been quite some time (if ever) that the US has experienced a pogrom. Some Jews seem to expect the appearance around the corner at any moment of a mob of Cossacks.
“If you reject that statement, you can still believe He is a great moral teacher, but you can’t believe He is the Messiah in any meaningful sense.”
Not really. Great moral teachers don’t lie about themselves and puff themselves up as something they are not. Great moral teachers don’t give people false hope, or say that they will do things that they are incapable of achieving. They don’t have to resort to “do as I say, not as I do”. If Christ wasn’t the Son of God, then he was a fraud, not a great moral teacher.