My professor was asked tonight, "Will Jehovah's Witnesses go to hell because they don't believe in the Trinity?"
Needless to say, the teacher tried answering it without offending anyone, which I respect in a professional classroom, but the answer came out in a somewhat relativistic way. But the truthfulness of the answer does not need to be disregarded. Ultimately, we know that they do not have the right view of God and of salvation, so how can it be obtained if they have false information? It just seems like we (Christians) have a hard time of explaining why people who "believe" in some type of Jesus are not going to heaven (cults).
People seem to want the heaven of the Bible, without having the God of the Bible. Hence the questions, "Can so and so go to heaven without believing in Jesus?" Or in other words, "Can so and so go to the heaven of the Bible without believing in the God of the Bible?" The answer is no.
The logic is simple:
If you have a false Jesus, a false Spirit, and a false gospel (II Cor. 11:4), then you have a false salvation. If the biblical gospel is not accepted (Galatians 1:6-9) then the result is to have a false gospel that does not provide salvation; there is no saving power in it.
Yes, it is a hard truth to admit and explain, but I think the easiest way (and most logical) is:
False Jesus + False Gospel = False Salvation