Here are some key covenants:
* Noahic Covenant: God promises never to destroy the earth by flood again, signified by the rainbow. It's universal, with grace for all creation.
* Abrahamic Covenant: God promises Abraham land, descendants (a great nation), and that through him, all nations would be blessed. This shifts from a universal to a more specific, chosen people.
* Mosaic (Sinai) Covenant: God makes Israel His chosen people, gives them the Law (Ten Commandments), and promises blessing for obedience, and curses for disobedience. This establishes Israel's identity and worship.
* Davidic Covenant: God promises David an everlasting line of descendants, establishing his kingdom forever. This points directly to the coming Messiah.