"God, being who He is, cannot cease to be what He is, and being what He is, He cannot act out of character with Himself. He is at once faithful and immutable, so all His words and acts must be and must remain faithful. Men become unfaithful out of desire, fear, weakness, loss of interest, or because of some strong influence from without. Obviously none of these forces can affect God in any way. He is His own reason for all He is and does. He cannot be compelled from without, but ever speaks and acts from within Himself by His own sovereign will as it pleases Him."
-A.W. Tozer on the faithfulness of God.