I am a firm believer that God is one and he became man in Christ Jesus. God is an infinite being of one mind. He fills all time and space.
Matthew teaches us that the Holy Spirit fathered the babe Christ Jesus in Mary (Matthew 1: 18-20). It was the Holy Spirit that took on flesh in Jesus here on earth the redeem man unto himself through the death, burial, and resurrection found in the books of Matthew, Mark, Luke, and John of the New Testament. Jesus is the son of God in that he had no natural father. It was the Spirit of God that created and inhabited the man Christ Jesus
God did not cease being everywhere when he took on flesh. Jesus revealed such to Nicodemus in John 3:13
"And no man hath ascended up to heaven, but he that came down from heaven, even the Son of man which is in heaven."
Paul also affirmed this in that said "In Him we live, and move, and have our being" (Acts 17:28)
Christ is the Holy Spirit in us... again referring back to the Apostle Paul...
He wrote to the Galatians," I am crucified with Christ: nevertheless I live; yet not I, but Christ liveth in me... (Galatians 2:20)
Christ is the Spirit that was in Paul and also in us...
So God is one... an Infinite being of one mind...and we must view him as such to start to understand who He is...