"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).
In your oun words, what does this verse mean?
If god is "unchangeable from all eternity to all eternity" how can he change?
I believe no matter what form God takes his doctrine and the laws of his Kingdom never changes and neither does his counsel to be received into that Kingdom
You tell me how did Jesus change one he was a divine spirit and the only begotten Son of Heavenly Father in the Flesh, after he did the will of His Father in heaven, he received his Glory of a resurrected body of Flesh and Bone.
1 Tim 3
16 And without controversy great is the mystery of godliness: God was manifest in the flesh, justified in the Spirit, seen of angels, preached unto the Gentiles, believed on in the world, received up into glory.
And what Glory did Jesus received it was he Glory his Heavenly Father gave unto him which is exaltation!
Jesus being the only begotten Son of Heavenly Father, his parentage was God the Heavenly Father eternal and his mother was Mary the mortal.
Jesus is Alpha and Omega
Were there not dimensional changes taking place from one kingdom to another kingdom as described in 1 Tim 3?
For each kingdom there is a set of laws that must be obeyed or one could not reside there.
You answered this question with the quote from Timothy -"And without controversy great is the mystery of godliness: God was manifest in the flesh, justified in the Spirit, seen of angels, preached unto the Gentiles, believed on in the world, received up into glory. " This is a Mystery, but it is described in Scripture. It is consistent with Scripture. It doesn't contradict Scripture.
A changing god is inconsistent with Scripture, and is contradicted by the BOM. You have to change the clear language of the BOM - ""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). "For do we not read that God is the same yesterday, today and forever, and in him there is no variableness, neither shadow of changing? And now, if ye have imagined up unto yourselves a god who doth vary, and in whom there is shadow of changing, then ye have imagined up unto yourselves a god who is not a God of miracles" (Mormon 9:9-10).
You say that these references to God refers to doctrines or laws. Well, that's not consistent with the clear language of Scripture.