The cross was an offense to some false teachers in Galatia, against whom Paul strongly preached. Jews had infiltrated the churches. They claimed to be Christians, but they brought a twisted, corrupted, distorted gospel with them (Gal. 1.6-9) as they attempted to bind the Gentile Christians under a host of Jewish laws which Christ had already eliminated through the cross.
Circumcision is not a sin in itself. Paul was circumcised (Phil. 3.5), and he even had Timothy circumcised for practical reasons (Acts 16.3), so he wasn’t condemning the actual act. He condemned it as a religious ritual as the Jews were teaching; they commanded all Christian men to be circumcised in order to be right with God. They made it a prerequisite to salvation.
In addition to circumcision, they also insisted Christians keep the special Jewish feast days (Gal. 4.10), adding them onto the list of things necessary for salvation. In other words, the Jewish Christians wouldn’t really accept the Gentile Christians as brothers until they measured up to their list of laws and demands.
Why did the cross offend these Jews? Paul preached against circumcision for salvation; the gospel eliminated the Law of Moses as necessary under Christ! He preached that Jesus abolished the Old Law and clearly stated that salvation is by faith in Christ apart from works of the law (Gal. 2.15-16). In fact, “if justification were through the law, then Christ died for no purpose” (Gal. 2.21), and “if a law had been given that could give life, then righteousness would indeed be by the law” (Gal. 3.21). But now that faith has come, we are not longer under the guardianship of the law (Gal. 3.25).
Christ has set us free in order that we may experience true freedom (Gal. 5.1). He has freed us from sin and law. The law actually binds us under sin, so Christ had to abolish the law in order that we might actually be free from sin! This is grace.
But grace offends the legalist (who believes he is saved by keeping a law) because grace says we are not saved by our work of keeping law; we are saved by Christ’s work of keeping the law and His awesome, powerful, sufficient sacrifice on the cross on our behalf. Just as the cross offended the Jews because it did away with their law, the cross offends legalists today because it does away with their law.
Who gets to make the list of laws which are necessary for entering into the kingdom of heaven? Only God holds that position. Is there a law Jesus expects us to submit to? Absolutely! If you don’t think so, you probably haven’t read the New Testament recently (you might refresh your memory starting with Matthew 5-7, Romans 6, James, and Galatians 5-6). But Jesus clarifies the place of law–law doesn’t save; He does. We keep His law because we are His children, not in order to make ourselves His children.
The legalist, however, so intent on keeping law, begins to make lists of actions and teachings which will keep a person out of heaven. Many such lists have been made which go far beyond gospel-level issues, and those lists divide good-hearted brethren. The legalist believes that eating (or not eating) certain meats will keep you out of heaven (Rom. 14; 1 Cor. 8). The legalist believes that observing (or not observing) certain special religious days will annul your salvation. The legalist believes you must add this or subtract that from your life in order to be saved. Their additions divide and do violence to the body of Christ! And that’s why Paul so vigorously opposed the mindset of legalism.
Paul could have made a long list to show why he was “qualified” to be saved, but he counted all his so-called qualifications as loss, he said, “for the surpassing worth of knowing Christ Jesus my Lord. For His sake I have suffered the loss of all things and count them as rubbish, in order that I my gain Christ and be found in him, not having a righteousness of my own that comes from the law, but that which comes through faith in Christ, the righteousness from God that depends on faith…” (Phil. 3.2-10).
Let us refrain from binding fellow Christians to our lists of laws! If Christ said to do it, then we shall do it. If Christ said to avoid it, then we shall avoid it. But let’s not add to or subtract from what He has said, and let us not think that we are saved by keeping His laws. We’ve been saved in order that we might keep His laws. There’s a big difference, and that difference has eternal consequences (Gal. 5.4)!