Immutability

God is immutable — he does not change in his being, character, or promises. "I the LORD do not change" (Mal 3:6); with him "there is no variation or shadow due to change" (Jas 1:17). Unlike us, he does not improve, decay, or shift with moods. What he is, he is consistently and forever.

This is not cold rigidity but the very thing that makes him trustworthy. A God who might change his mind about you tomorrow could never be rested in; an unchanging God can be. His love for his people does not cool, his promises do not expire, his character does not erode. (Scripture's language of God "relenting" describes his consistent response to changed human situations, not a change in God himself.) The same God who was faithful to Abraham is faithful now and will be faithful at the end.