How are we apart of God’s old testament covenant?

How are we apart of God’s old testament covenant?

In the covenant that God made with Adam He said that jesu would strike satan down for him and he did it for us to. In the covenant god made with Abraham he said he would make his descendants into a great nation, we aren’t technically Abraham’s descendants but because of God’s promise of salvation we are his children. In God’s covenant with Moses he said he promised never again to destroy the earth. In the covenant with David god promised He would establish his kingdom forever and his descendants would rule on the throne forever and Jesus is David’s descendant.