Galatians 4:4-5

And I will put enmity between thee and the woman, and between thy seed and her seed; it shall bruise thy head, and thou shalt bruise his heel. – Genesis 3:15

Many refer to this verse in Genesis as the Proto-Evangelium. This term, Proto-Evangelium, simply translates to mean “first gospel.” It is called that, because as we move through the canon of Scripture, it is this text which is seen as the first time the promise of the gospel is made to mankind. In the Garden of Eden, Adam and Eve sinned following the temptation of the Serpent. In response, God issued the condemnation that eventually the seed of the woman would crush the serpent. From that point forward, we see all of mankind in turmoil with the serpent, Satan, until the perfect descendant of the woman, Jesus, came and defeated him.
As we look to Galatians 4, there are two things that we must realize that Paul is teaching about Jesus. In verse 4, Paul says that God “sent forth His son.” In order for God to “send forth” Jesus, that means that Jesus already existed. Jesus was not a creation of God that just happened to come along when the time was right. Rather, in God’s perfect time table, the pre-existent, eternal Jesus was “sent forth” by God. But Paul doesn’t just speak of His eternal Deity.
Paul continues with “born of a woman.” What an incredible phrase to use when speaking of Jesus. There is no better phrase to illustrate the humanity of Jesus. Paul could have simply said that Jesus was “sent forth” and moved on, but instead, Paul points us back to the garden and the Proto-Evangelium promise that one day the descendant of the woman would come to crush the serpent. Jesus had now come, and He was fully God, and fully man.
Paul finally says why Jesus came, “to redeem them that are under the law.” The word “redeem” means to “ buy back” Literally, it has the idea of showing up at a slave market and purchasing someone. But how did Jesus redeem mankind? Jesus lived a perfect life and died a substitutionary death so that He could redeem mankind. It was necessary also that Jesus be fully God in this work of redemption, because there was an infinite debt owed for the sin of mankind. In His Deity, Jesus could offer himself as the infinite, eternal sacrifice for sin against the eternally holy God. In His humanity, Jesus could become the substitute for mankind having been made “in the likeness of human flesh.”
The beauty of the entire redemption process by Jesus, is that we who were once estranged slaves, apart from God, now have access to Him through His son. Instead of being slaves, we now have access to God as the children of God, “that we might receive the adoption of sons.” Through the life, death, Deity and humanity of Jesus, our Redeemer, we have been forgiven and adopted.

Food For Thought: What is the Proto-Evangelium? In what way did Paul reference it in Galatians 4:4-5?