Jesus in the Old Testament: Reconciled through Abraham's Seed

I have written previously about God's covenant with Abraham and about how the blessings of this covenant would be for all people. In Genesis 17 we read the record of God speaking to Abraham and explaining to him the beginning details of how this covenant would be fulfilled. 

Genesis 17:19; Then God said, "Yes, but your wife Sarah will bear you a son, and you will call him Isaac. I will establish my covenant with him as an everlasting covenant for his descendants after him."

Paul explains for all in Romans 9 how this covenant with Abraham affects us today, whether we are of the Jewish line coming from Abraham or not.

Romans 9:7-9; It is through Isaac that your offspring will be reckoned. In other words, it is not the children by physical descent who are God’s children, but it is the children of the promise who are regarded as Abraham’s offspring. For this was how the promise was stated: “At the appointed time I will return, and Sarah will have a son.

We are reconciled to God through this covenant - not because we come from Abraham's blood line but because Jesus came from Abraham's blood line. And through the birth, death, and resurrection of Jesus, we are reconciled.