“God does not change. Let us draw out this thought.
1. God’s life does not change. He is “from everlasting” (Ps.93:2), “an everlasting King” (Jer. 10:10), “incorruptible” (Rom. 1:23), “who only hath immortality” (1 Tim. 6:16). “Before the mountains were brought forth, or ever thou hadst formed the earth and the world, even from everlasting to everlasting thou art God” (Ps. 90:2). Earth and heaven, says the psalmist, “shall perish, but thou shalt endure: yea, all of them shall wax old like a garment; as a vesture shalt thou change them, and they shall be changed: but thou art the same, and thy years shall have no end” (Ps. 102:26 f.). “‘I am the first,’ says God. ‘I am also the last’” (Isa. 48:12).
Created things have a beginning and an ending, but not so their Creator. The answer to the child’s question, “who made God?,” is simply that God did not need to be made, for He was always there. He exists for ever; and He is always the same. He does not grow older. His life does not wax or wane. He does not gain new powers, nor lose those that He once had. He does not mature or develop. He does not get stronger, or weaker, or wiser, as time goes by. “He cannot change for the better,” wrote A. W. Pink, “for He is already perfect; and being perfect, He cannot change for the worse.” The first and fundamental difference between the Creator and His creatures is that they are mutable and their nature admits of change, whereas God is immutable and can never cease to be what He is.
As the hymn puts it,
“We blossom and flourish as leaves on the tree,
And wither and perish-but nought changeth Thee.”
-J. I. Packer, Knowing God.