Let me begin by simply asking a question. Do you believe that Jesus and the Holy Spirit are God?
Is Satan not called god?
The god of this age has blinded the minds of unbelievers so they cannot see the light of the gospel of the glory of Christ, who is the image of God. (2 Corinthians 4:4 [BSB])
Or even Moses?
And the LORD said to Moses, “See,
I have made you like God to Pharaoh, and your brother Aaron shall be your prophet. (Exodus 7:1 [ESV])
So if Jesus Christ is lesser than God,
You heard me say to you, ‘I am going away, and I will come to you.’ If you loved me, you would have rejoiced, because I am going to the Father, for
the Father is greater than I. (John 14:28 [ESV])
Jesus said, "Do not hold on to me, for I have not yet ascended to the Father. Go instead to my brothers and tell them, 'I am ascending to my Father and your Father,
to my God and your God.'" (John 20:17 [NIV])
Yet he is called God also,
In the beginning was the Word, and the Word was with God, and
the Word was God. (John 1:1 [ESV])
Did it not occur to you he is simply called God because of
the authority given to him by God,
Then Jesus came to them and said, "
All authority in heaven and on earth has been
given to me. (Matthew 28:18 [NIV])
To be the very exact representation of God,
The Son is the radiance of God's glory and
the exact representation of his being, sustaining all things by his powerful word. After he had provided purification for sins, he sat down at the right hand of the Majesty in heaven. (Hebrews 1:3 [NIV])
Just as Adam was made in the image of God,
So God created mankind in his own image, in the image of God he created them; male and female he created them. (Genesis 1:27 [NIV])
And subsequently gave him authority over all earth,
God blessed them and said to them, "Be fruitful and increase in number; fill the earth and subdue it.
Rule over the fish in the sea and the birds in the sky and over every living creature that moves on the ground." (Genesis 1:28 [NIV])
Then God said, "Let Us make man in Our image, according to Our likeness; and
let them rule over the fish of the sea and over the birds of the sky and over the cattle and
over all the earth, and over every creeping thing that creeps on the earth." (Genesis 1:28 [NASB])
Yet Jesus Christ was given the highest measure of authority, over heaven and earth, hence why his name is the greatest,
Therefore God has highly exalted him and bestowed on him
the name that is above every name, (Philippians 2:9 [ESV])
Because EVEN THOUGH THERE IS ONLY ONE GOD, THE FATHER, just like any being that is called "god", Jesus Christ is called "God" because of the authority given to him by God TO BE AS GOD, his very own representation in creation.