Jesus and New Testament authors repeatedly apparently talk about the Father as Jesus' God. This Biblical Unitarian article collects some examples:
Ephesians 1:17
I keep asking that the God of our Lord Jesus Christ, the glorious
Father, may give you the spirit of wisdom and revelation, so that you
may know him better.
Revelation 1:6
And has made us to be a kingdom and priests to serve his God and
Father– to him be glory and power for ever and ever! Amen.
Revelation 3:12
Him who overcomes I will make a pillar in the temple of my God. Never
again will he leave it. I will write on him the name of my God and the
name of the city of my God, the new Jerusalem, which is coming down
out of heaven from my God; and I will also write on him my new name.
Even in the book of Revelation (after his death, resurrection, and
ascension), when Jesus has all authority in Heaven and on Earth,
seated at the right hand of God, he still says “my God.”
1 Peter 1:3
Praise be to the God and Father of our Lord Jesus Christ! In his great
mercy he has given us new birth into a living hope through the
resurrection of Jesus Christ from the dead
John 20:17 (NASB)
Jesus said to her, “Stop clinging to me, for I have not yet ascended
to the Father; but go to my brethren, and say to them, ‘I ascend to my
Father and your Father, and my God and your God.’”
Romans 15:6
So that with one heart and mouth you may glorify the God and Father of
our Lord Jesus Christ.
2 Corinthians 1:3
Praise be to the God and Father of our Lord Jesus Christ, the Father
of compassion and the God of all comfort.
2 Corinthians 11:31 (KJV)
The God and Father of our Lord Jesus Christ, which is blessed for
evermore, knoweth that I lie not.
To this can be added other verses, such as Hebrews 1:8-9.
"But about the Son He says: “Your throne, O God, endures [alt. 'Your throne is God'] forever
and ever, and justice is the scepter of Your kingdom. 9 You have loved
righteousness and hated wickedness; therefore God, Your God, has
anointed You above Your companions with the oil of joy.”" (Berean Study Bible)
The assertions that Jesus has a God cut across the New Testament, including St. Peter, St. Paul, St. John, and the author of Hebrews' writings. They are made both by Jesus himself before he ascends, and by others after He ascends.
According to Trinitarian theology, does only God the Son have a God? Or does God the Father also? God the Holy Spirit?