Because you asked a reasoned question instead of attacking, I will try to answer your question.
If you believe in the trinity then this would be hard to understand. We believe the Godhead is made up of three separate beings God the eternal father, Jesus Christ and the Holy ghost.
I you read the entire Moroni 9 then you see he is talking about Christ and God. God being the eternal Father and Jesus Christ his son.
If you have a Book of Mormon read the the correlating references found in the Old and New testament for chapter nine.
“If you believe in the trinity then this would be hard to understand. We believe the Godhead is made up of three separate beings God the eternal father, Jesus Christ and the Holy ghost.”
My friend, the LDS church rejects the concept of One God in Three Persons, the Holy Trinity. You just spelled it out for all to consider carefully.
This concept is at the core of Christian belief. And it has everything to do with, Who is Jesus? Christians have unwavering faith that Jesus is the great “I AM”. He tells his deciples, “If you have seen me, you have seen the Father.”
"I know that God is not a partial God, neither a changeable being; but he is unchangeable from all eternity to all eternity" (Moroni 8:18).
Two questions:
In your oun words, what does this verse mean?
If god is "unchangeable from all eternity to all eternity" how can he change?