A great attribute of God is faithfulness. He can not deny Himself because it is an attribute of God as such, and we must know this, that even though we are unfaithful, God remains faithful. God’s faithfulness goes beyond our actions or our behavior, God is God, and fulfills all His promises.
We human beings are given to promise and not to fulfill, even, sometimes we even forget what we have promised and unfortunately that belongs to our nature, but the nature of God is totally different from that of us, when God promises something, He does not forget what He has promised. He is God, strong and powerful God, the God who showed part of His power to the people of Israel.
The Bible says:
9 Know therefore that the Lord your God is God; he is the faithful God, keeping his covenant of love to a thousand generations of those who love him and keep his commandments. 10 But
those who hate him he will repay to their face by destruction;
he will not be slow to repay to their face those who hate him.
11 Therefore, take care to follow the commands, decrees and laws I give you today.