It's an old game. One can take Bible verses to prove or to disprove doctrines like the trinity. (Ex.: "I and my father are one." vs. "My father is greater than I.") It largely depends upon the viewpoint of the reader. But the fact that the trinity doctrine took centuries to define should, at least, bring into question just how important that doctrine really is. In the fourth century when the controversy tore the Catholic Church apart the penalty decided by Constantine seemed to be exile for either Arians and Trinitarians. Both were in favor of the emperor and his son at one time or another.
I agree with Verodico that the earliest Jewish Christians had no concept of the trinity doctrine and that the doctrine slowly developed with the advent of pagan Gentiles coming into the church. This fact again would bring into question the claim that the trinity is the "central doctrine of Christianity." If anything, it bespeaks of the effort of the Gentile leaders to disclaim the Jewish roots of their faith. What better strategy to alienate the Jewish believers than to proclaim Christ as God....something that would be repulsive to any Jew.