He hath remembered his covenant for ever, the word which he commanded to a thousand generations. -Psalm 105:8 (KJV)
I have lost track of how many times in my life I have promised something to someone [or to God] that I failed to fulfill. So many jackpots to escape that it became a common practice to make assurances to others about things that would never become reality. So often I have made promises to God in the morning, only to be quickly forgotten as the cares of the world took over as the day wore on.
God is not a man, that he should lie; neither the son of man, that he should repent: hath he said, and shall he not do it? or hath he spoken, and shall he not make it good? -Numbers 23:19 (KJV) I have never meant anyone who hasn’t told a lie (or many of them, for that matter). If I did, I think I would immediately conclude that they were lying to me!
Know therefore that Jehovah thy God, he is God, the faithful God, who keepeth covenant and lovingkindness with them that love him and keep his commandments to a thousand generations, -Deuteronomy 7:9 (ASV) God is consistent. We know from scripture that He does not change: For I, Jehovah, change not; therefore ye, O sons of Jacob, are not consumed. -Malachi 3:6 (ASV)