EB, thanks for the reply. Based on your observations, it is obviously true that many Trinitarians consider the Trinity essential for salvation. I would say there are also many who do not. I received a letter from a popular ministry group on the subject, as we discussed godhead. They believed because we accepted Jesus as Divine and human, as the Son of God, to not be heretical (although they were adamant we were in error).
"The Faith" is a connection to the Gospel. Everything that Jesus said. "I am my Father am One." That He is the Messiah, God in flesh.
Paul's mention of "another Jesus" (
2 Corinthians 11:4), is also in the context of "another Gospel" and "another spirit." His detractors were either Judaizers, which had less to do with godhead than it did salvation by and through the Law, or they were Gnostics, who didn't believe Jesus to be fully human at all, thus denying the reality that He was the Son of God.