When God called you to Christ, He also called you away from bondage to law. Before you trusted Christ, you were bound to God's law the way a condemned man bound to the anchor that is dragging him to the bottom of the sea is bound to die. See Romans 7:1-8.
Paul's language of bondage-to-law does not mean "the obligation to think and act in a godly way." All Christians are always obligated to do right. We have not been freed from moral obligations to man and God. The issue is, which obligations, and more importantly, why do we keep them?
No, when Paul says "bound by law", he means obligated to any and every aspect of Moses' law for everlasting life. This includes all ten of the Ten Commandments. Only Jesus Christ's death on the cross can free you. He lived the only perfect human life, then died the only satisfactory human death, on behalf of all sinners. He left absolutely nothing more for you to do, to inherit everlasting life.
Christ's death means you are freed from the whole Law -- not just the ceremonial laws like circumcision or the festivals, but every part of the law, including the Ten Commandments. You do not need to keep any of the law to receive everlasting life, or to be God's child. This idea is baffling to every legalist -- Protestant or Catholic, Muslim or Jew. But it is the Good News of Christ.
Now, Paul (anticipating obvious objections), says that God didn't give you this freedom from the Law as an opportunity to indulge your sins. Instead, Paul commands us to love one another (v. 13-14). Here again we see how Paul distinguishes between:
The failure to see these two distinctions cause great confusion between denominations. The traditional Reformed churches do not adequately distinguish between Moses Covenant and the New Covenant of our salvation. They lump the two together, as equal manifestations of the covenant of grace. As a result, they unintentionally taint the liberty of the New Covenant with Jewish legalism.
On the other hand, some dispensational churches will not acknowledge that a text like Galatians 5:13 is a commandment. They are allergic to even the word "commandment." They have confused this being the age of grace with the false idea that the New testament issues no commandments. This was the theology-of-lawlessness taught to me by "Darbyites", when I was a Christian youth.
What is Paul saying? Moses' Covenant was fulfilled by the cross, and ended by the cross. Moses' Covenant ceased. It was replaced -- not augmented or fulfilled, but replaced -- by the New Covenant in Christ's blood. This New Covenant also teaches us moral commandments, but we obey them out of life, not for life.
Paul is keeping the Biblical balance. You are free from Moses' system, but not free to sin.
The Galatian Christians were listening to some local preacher, who was telling them that they needed to be circumcised, in addition to trusting in Jesus Christ, to be saved. Paul made it clear to them that circumcision was only one law in a lengthy law (which you can find in Exodus and Leviticus) which condemns us for our failure to keep it perfectly.
Examples of this Jewish error in the Christian history is Roman Catholicism and Eastern Orthodoxy. They both teach that we believe the Gospel so that we may keep the Law. Then, by keeping the Law, combined with the so-called sacraments and the redeeming suffering of Purgatory, we might be saved. In opposition to this ugly message, Paul says that we believe the Gospel instead of keeping the Law.
This is why Paul says that the faith + law message is not from God (v.8). Even just a little pinch of this false teaching was spreading through the whole congregation, and poisoning it (v.9).
Paul expresses confidence that the Lord will keep His children faithful to the Gospel. It is interesting to me that Paul does not express any confidence in the Christians. In fact, he was shocked that they were in the process of defecting from the faith (1:6). But Paul's confidence was in the Lord (v.10a).
This is a fine illustration of Paul believing in God's sovereignty and man's responsibility at the same time. Paul wrote the book of Galatians to keep them anchored in the Gospel. But he is, at the same time, confident in the Lord's power and commitment to make sure they take no other view. He had not changed his message, as it appears someone was claiming (11). If he had changed to a message of faith + works, the false preachers would have stopped persecuting him.
The sovereign Lord of salvation does not allow His true children to completely or permanently defect from the faith. This false gospel of faith + works tests the reality of people's professions of faith, and separates the true wheat from the false tares. A person who knowingly embraces a message of faith + works exposes himself or herself as one who was never truly converted.
Paul expects God's judgment to fall on whoever was the mastermind of this malign influence (v. 10b). In fact, Paul wishes great ill upon the false teachers, by wishing they would not just stop at circumcision and go ahead and completely emasculate themselves (v.12)! This verse illustrates the prophetic severity of the Spirit speaking through the apostle. Verse 12 is a good New Testament example of an Old Testament cursing-psalm.
Jewish cultists wanted the Galatian Christians to undergo circumcision, in addition to their faith in Christ, with the idea that doing that would save them (see Acts 15:1). They were synthesizers. They wanted to blend Jesus Christ with keeping the Old Testament law.
Paul makes it clear. You cannot blend faith in Jesus Christ for salvation with law-keeping. It's an either/or, not a both/and. You may not combine them. You must chooses between them. Are you going to rely on Christ's death to make you right with God, or your own performance? The first option saves you, the second option condemns you.
This is why Paul says that, if they choose the circumcision route, Jesus Christ is of no benefit to them. The Galatians were also naive. It sounds as if the Jewish cultists were saying, "Just this one thing, just circumcision, that's all, then you're done." But Paul, a Benjaminite rabbi trained in the heart of Jerusalem, knows that you must keep the entire Law, down to the smallest aspects, if you decide to live by Law. You are not allowed to pick-and-choose between the laws you like and the laws you don't.
Any Christian who tries to secure his own salvation by keeping moral laws has cut himself off from Christ, and has abandoned the grace of God. The Law demands perfect righteousness. Our only hope for perfected righteousness is Christ, returning as He promised. By the Spirit's power, through faith, we eagerly wait for Him to come back.
Only faith in Christ and His gospel, working through the love that faith generates in our hearts, counts for anything. Whether you are Gentile or Jew, uncircumcised or circumcised, is irrelevant.
You must choose between salvation by Law or salvation by Christ. Which will you pick?
In the old Roman games, there was a gladiator called the retiarius who fought with a net. He sought to entangle his opponent with a mesh, then stab him with a trident. Satan does the same thing with legalistic preaching. He seeks to enmesh the believer's conscience with pride of good works, and our ever-lingering unbelief toward the work of Christ on the cross. Christ's death frees us from fear, because He paid the full price for our sins. His death also frees us from the Old Covenant, because His death establishes the New Covenant in its place. But Satan wants to obscure the cross and turn our minds to our own works, or the works of a priest. Satan seeks to get us down, get his knee into our back, and lock the yoke of God's law back down around our neck. But Paul says in this verse to take a militant stance against Satan's entangling strategy Do not tolerate works-salvation teaching, not even for a moment! This is a non-negotiable area of Christian life and ministry.