Isa. 43
10 Ye are my witnesses, saith the LORD, and my servant whom I have chosen: that ye may know and believe me, and understand that I am he: before me there was no God formed, neither shall there be after me.
Because Jesus was the only begotton Son of Heavenly Father!
It polite to flag one when you try to assail them!
Resty, there is no disagreement that God IS and exists un created. The heresy in Mormonism as conveyed by sevenbak is that we humans were with God in the beginning, thus humans, at least Mormon humans, are not created beings.