I mean that the heir, as long as he is a child, is no different from a slave, though he is the owner of everything, but he is under guardians and managers until the date set by his father. In the same way we also, when we were children, were enslaved to the elementary principles of the world. But when the fullness of time had come, God sent forth his Son, born of woman, born under the law, to redeem those who were under the law, so that we might receive adoption as sons. And because you are sons, God has sent the Spirit of his Son into our hearts, crying, “Abba! Father!” So you are no longer a slave, but a son, and if a son, then an heir through God.
~ Galatians 4:1-7
Seeking to expand the idea of Christians being free from the law, Paul now goes into detail about what he meant in that a slave who is adopted by his owner no longer is under the same obligation as he was before. As a slave, you are bound to do what you’re told, but as an adopted child, you have the freedom to do as you please. Practically, it works like this – Jews who are under the bounds of legalism inside of the law cannot eat pork or shellfish and are bound to do no work on the Sabbath. Those who are freed in Christ, however, are free from those limitations and can eat pork and shellfish, and since we find our rest in Christ (the Lord of the Sabbath), we are not under the same legal restrictions that they were. Granted, some laws remain, the moral laws, for instance, as well as those proclaimed to us in the New Testament (abstain from meat sacrificed to idols and sexual immorality) but that’s a far cry from the legalism that Jews experienced under the old covenant.
Paul explains that God chose to send His Son at a time of His choosing to live according to the law of God, in a manner that no one could do on their own, and as a result we are freed from the curse of that law. We are no longer bound to it, but freed from it by our rebirth in Christ who, through His adherence to it, and our relationship to Him, has fulfilled the law for us in our place. His fulfillment of the law, now that we are in Him and He in us, carries over to us and it no longer has any control over us.
I know this explanation is a little tired, but I think it may help here. Let’s say that you’re speeding along the road and, in your ignorance, you blow through an area that was set aside for a blind children’s convention. You’re pulled over and the officer says that he clocked you going 125 mph in a 25mph area and that you had endangered the lives of many special needs children. He takes you to jail and the next day you learn that the fine for doing so is $145,000 and if you can’t pay it then you’re looking at 30 years in prison. The only problem is that you don’t have any money at all. You’re busted, dead to rights, and there is no hope for you. The judge is about to drop his gavel and sentence you to prison when a man walks into the courtroom. You’ve never met him and you have no idea who he is but he runs up to the judge and whispers something into his ear. A moment later the gavel drops and the judge orders, “Release the man and take my son into custody!”. You’re shocked to hear that the man says that he knows who you are, despite the fact that you have no idea who he is, and he loves you so much that he’s offered to take your place. Justice is fulfilled and the law no longer has any hold over you.
This, while a weak example, describes why the law no longer has any hold over us as Christians. The difference is that the penalty for our sin is death and Jesus, as our substitute, took our place on the cross of suffering, was tortured, mocked, beaten, and eventually killed while taking our sin on Himself. When He died, He redeemed us and set us free from the bondage to the law – it no longer has any claim over us. More than that, as a result of His death in our place, and us trusting in Him alone for our salvation, we have His righteousness deposited into our account and we are adopted into the family of God. We, with the Holy Spirit living inside us, are able to call out to the Father and call the great, I AM, “Father”, and He will listen to us just as if we were His own Son.
Thus we are no longer a slave through the law, but a child of God, adopted through the blood of Jesus.