Well there are a good many verses in the Bible that try to express the nature of Jesus and His relationship with God. When compiled in their entirety a general theme emerges of a Father, a God, a supreme being, an eternal, indivisible spiritual essence that engages with humans via a Messenger that he has prepared to deliver His Message.
Jesus represented God, and in so doing was God in the sense that Jesus expressed the Will of God as He was bidden to do so. But stepping back from that we see that this in no way suggests that Jesus was literally God, an aspect of God or part of some three part reality which is really one part, but it's three.
For humans Jesus is as close as they will ever come to God. He had the authority and expressed the Will of God, but God is transcendent from division, from descent into the imperfection of its own Creation. By suggesting Jesus was God we have reduced God to the imperfections of human form, to a being that needed to eat, defecate, had body odour and bad breath, had dirt on His body and was put to death by mere humans. That is a really strange version of God and it takes little insight to realise that this belief is as close to heresy as one can get.
I do not know what directed the vote to its outcome, but it can be speculated that Constantine had a very specific requirement of his Christianity to be used politically, it was the best religion to unite his imperial cult. Clearly it was in the best interests of those bishops gathered to determine that Jesus was indeed God and part of a similar trinity to that which already existed for the Romans and that Constantine was then in communion with and directed by God Himself in the form of Jesus.
The bishop voters were under pressure to find a way of unifying Rome's three god trinity with Christian belief. In establishing the Trinity as we know it today Constantine had them blend Christianity into the Roman religion, meaning that it was but a short step for the followers of the old Roman three god religion to become Christians.
It's a history worth studying and it becomes clear why the doctrine of the Trinity was an essential outcome that was a done deal from the get-go when those bishops got together. I imagine the bishops resisted as best they could but the consequences were too great not to capitulate, so they found certain scriptures that seemed to soften the blow of bowing to the authority of Constantine.
