its not so much showing where the bible specifically states that "you must believe in the trinity" or "you must believe in the deity of Christ" to be saved- obviously it doesnt say that or we wouldnt be having this discussion.
But you have to believe Jesus. You will likely state that Jesus never claimed deity for himself; i would simply disagree. It is such an accepted fact that it is a basic cornerstone of the Christian faith.
Greg Koukl says this:
f you reject such a thing, I don't see how you can then say I have put my faith in Jesus because the Jesus that you put your faith in is not the Jesus of the Scriptures, and it is only the Jesus of the Scriptures who really saves you.
So I think that it's actually very critical and I think it's important to point out that Paul himself talked about another Jesus that was preached that some unfortunately accept, but a Jesus that is contrary to the Jesus of Scriptures. In fact, Jesus warned in Matthew 24 that one characteristic of the end times is the fact that false messiahs would come and claim to be someone special and mislead many. And I think that false messiahs are individuals who claim to be messiah or else substitute definitions for the Jesus of Scripture. I think the denial of the deity of Christ is such a substitution.
The Scripture teaches clearly not only that any old god won't do--and we see that in statements like Exodus 20:2-3, "I am the Lord your God who brought you out of the land of Egypt, out of the house of slavery. You shall have no other gods before me." The first commandment in fact. We must have the correct God before us. By the same token, any old Jesus won't do either. Jesus says in John 8:24, "Unless you believe that I Am, you shall die in your sins." According to Jesus it was very critical that we have a particular belief about him, and if we don't then we are lost in our sins.
It isn't enough to simply believe in Him. And by the way, that text in John 8 is when Jesus was addressing particular people who had believed in Him in some fashion. But one needs to have an accurate belief in Jesus, not just any belief in Jesus in order for the true Christ to be their savior. I think that those are very critical distinctions and we have to hold to those if the word Christian is going to continue to mean something in particular and not just any religious thought that has to do with some man or any man named Jesus.
So, i guess the question becomes whether anyone who is not a "christian" can be saved.
Further, I would be very uncomfortable suggesting great men of God of the past (like Tozer) were simply mistaken about this key doctrine.
TK