Philippians 2:9-11
Wherefore God also hath highly exalted him, and given him a name which is above every name: That at the name of Jesus every knee should bow, of things in heaven, and things in earth, and things under the earth; And that every tongue should confess that Jesus Christ is Lord, to the glory of God the Father.
It is the name of Jesus we find in the New Testament, not the name of another lesser god, but the name of the same God who the Old Testament writers knew as YHWH. There is no greater demonstration of God's justice and love than the work he came to do at the cross. His justice required that sin must be paid for, His love caused Him to become a man to pay that price. We don't need to understand how He did it, but that He did it. Jesus is the Alpha and Omega, the first and the last, who was dead and is alive forevermore.
The evidence from the scripture far outweighs all the objections. It outweighs objections that it is not scriptural, it outweighs the objections that it was from pagan religions, or that it is not understandable, or that it is not possible. For the scriptures declare that each of the three persons are the one God.
Those who say that Jesus was a created being belittle the meaning of the cross, and the depth of God's love for us. It was not a mere exchange to pay off a debt owed: a created life for a created life. The price that was paid, a created being could not satisfy, nor could such a task be entrusted to a created being. There was never any doubt that Jesus would succeed, for God had promised it from the very beginning of creation. Jesus remained faithful as only God in human flesh could do.
Jesus tells us that God is a Spirit, and those who worship Him must worship Him in spirit and in truth. God's Spirit is personal, not an active force. Those who reject the idea of a personal Spirit also reject what that personal Spirit inspired. And to reject the work of the Spirit is the only unforgivable sin.
God asks us to reason together, to prove all things, to search the scriptures. The scriptures from beginning to end speak of Jesus. He is there if you look, but if you reject who he is you will never see him, and you will never find him.
The sad thing in this world today is that most people are satisfied with a manufactured view of Jesus. He is to them a great man, a prophet, an angel, a lesser God, a fanatic, or a fairy tale. They trust what someone tells them about Jesus rather than opening God's Word and let the Spirit lead them. God's Word tells us who Jesus was, the Son of God, the image of God, the fullness of the Godhead, the Creator, the I AM, the Alpha and Omega.
Belief in the trinity is not essential knowledge for salvation, but no one who is truly saved can continue to reject the trinity.
John 8:24
I said therefore unto you, that ye shall die in your sins: for if ye believe not that I am he, ye shall die in your sins.