We cannot approach the Bible with wisdom and “reason together” if we must invent and use non-biblical phrases to support our theology. The Bible calls Jesus the “Son” of God for the simple reason that he had a beginning. Jesus had been part of God’s plan since the foundation of the world, but he began his actual life when God “fathered” him and Mary conceived him in her womb. There are many verses where Jesus and God are portrayed as two separate beings and there are too many examples to list, but just to mention a few we can look at when Jesus told the rich young ruler that he was not good, but “God” was good. Also Jesus grew in favor with “God” and with men, and he told his disciples“ Believe in God; believe also in me."
I find it interesting that the Church Epistles were authored by both God and Christ and we see this in 1 Corinthians 1:3 that says “Grace to you and peace from God our Father and the Lord Jesus Christ.” There's a lot of Scripture that shows Jesus to be separate and distinct from“God” which is what the people of the time believed and expected. The Trinitarian explanation of these verses is that Jesus is God and so“ God” means “the Father” when Jesus speaks of himself and “God.” But the Bible never says that. It's only because Trinitarian doctrine asserts that Jesus is God that the assumption is made that “God” means “the Father” when Jesus and God appear together.