Deuteronomy 7:9
Know therefore that the LORD your God is God, the faithful God who keeps covenant and steadfast love with those who love him and keep his commandments, to a thousand generations.
The problem with the Old Covenant was that it was made with sinful mortals. As faithful as God was, we were unfaithful and, apart from grace, would always be so. The glory of the New Covenant is that it is made between God the Father and God the Son. God the Son always is faithful to the covenant, so the covenant remains, not merely to a thousand generations but to a million or a billion if necessary. And because God the Son is a man in the likeness of men, we humans share in that covenant for all time. Today, thank God for his miraculous faithfulness.