Mormonism vs. God's Word
God was God from all eternity
We have imagined and supposed that God was God from all eternity. I will refute that idea, and take away the veil, so that you may see.
Joseph Smith, The King Follett Sermon (1844)
What God says
In the beginning was the Word, and the Word was with God, and the Word was God. He was in the beginning with God. All things were made through him, and without him was not any thing made that was made
Before the mountains were brought forth, or ever you had formed the earth and the world, from everlasting to everlasting you are God.
God is one
I have always declared God to be a distinct personage, Jesus Christ a separate and distinct personage from God the Father, and the Holy Ghost was a distinct personage and a Spirit: and these three constitute three distinct personages and three Gods,
Teachings of Prophet Joseph Smith, p. 370 (emphasis mine)
What God says
I and the Father are one.
Jesus (John 10:30)
Thus says the Lord, the King of Israel and his Redeemer, the Lord of hosts: “I am the first and I am the last; besides me there is no god.
And this is eternal life, that they know you the only true God, and Jesus Christ whom you have sent.
“You are my witnesses,” declares the Lord, “and my servant whom I have chosen, that you may know and believe me and understand that I am he. Before me no god was formed, nor shall there be any after me.