Paul gives his understanding of who Christ is and how He fulfilled the Scriptures.
Now remember, Paul was a Pharisee of the Pharisees, he knew the Scriptures. In fact, most of the things that he writes in his letters, he quotes from the Old Testament prophets. You got to get a hold of this because most people, when they read the Old Testament and then they see that division in the Bible that says “New Testament”, they think everything there is NEW.
Everything after the New Testament is NOT NEW. It is recording and reemphasizing what was spoken by the prophets in the Old Testament. Most of the things that Jesus spoke in Matthew, Mark, Luke, and John, He was quoting from the Old Testament, because why? He fulfilled the Law, He came to fulfill everything that was spoken about Himself.
This is only a small portion of the teaching, “Deliverance from Sin & Death“.