God is immutable.
All that God is, He has always been. All that He has been and is, He will ever be.
He cannot change because He is perfect and will remain perfect.
25 In the beginning you laid the foundations of the earth, and the heavens are the work of your hands.
26 They will perish, but you remain; they will all wear out like a garment. Like clothing you will change them and they will be discarded.
27 But you remain the same, and your years will never end.
28 The children of your servants will live in your presence; their descendants will be established before you."