Paul begins his ethical appeal with a second declaration of freedom: You, my brothers, were called to be free (v. 13). This declaration echoes the central points of his first declaration in chapter 5 ("It is for freedom that Christ has set us free" ). Both declarations focus on the initiative of God: Christ's action set us free! God's call set us free! When the whole human race was hopelessly locked up under law, imprisoned by sin, "God sent his Son" into human history to set us free. When we were enslaved, "God sent the Spirit of his Son into our hearts" to set us free. Our freedom is not the result of our decisions or our actions. God acted in history on the cross and through the resurrection to set us free. God acted in our hearts by his Spirit to set us free. The gracious initiative of God is underscored by Paul's repetition.
Both declarations of freedom also emphasize that freedom is the purpose of God's action in Christ. The NIV translation brings this out in verse 1 but not in verse 13. Paul puts the purpose of God's action right at the beginning of both sentences: "For freedom . . . ! To freedom you were called, brothers!" What is the purpose of your Christian life? Freedom in Christ! Paul blasts out these trumpet calls of freedom to Christians who are in danger of putting themselves under a heavy yoke of slavery. Their immediate goal is circumcision--painful discipline under the law. Their larger purpose would then be, as Paul informs them in verse 3, the obligation to obey the whole law. Their total preoccupation would be to learn the Jewish traditions and keep the Jewish customs. Paul knows very well from his own experience (1:14) that that road does not lead to freedom. So he repeats his declaration of freedom to emphasize the new purpose of their life in Christ: they are called to freedom from slavery under the law.
So far we have seen two similarities between these two declarations of freedom in verse 1 and verse 13. Now we need to observe a great contrast. After the first declaration Paul gives a command to protect freedom by refusing to accept the "yoke of slavery." After the second declaration Paul gives a command not to use freedom to indulge your sinful nature but to serve one another in love. In other words, we are first told not to lose our freedom by turning back to slavery; then we told to use our freedom by entering into slavery.
No doubt Paul sets up this apparent contradiction as a kind of warning signal. Paul clearly sees the danger that his teaching about freedom from slavery under the law might be interpreted to mean freedom to do whatever our selfish desires lead us to do. A more literal translation of the second phrase of verse 13 than we have in the NIV is "only do not use your freedom as an opportunity for the flesh." The Greek word I have translated as "opportunity" was originally a military term for "the starting point of a military offensive" or "a base of operations." It was commonly used to mean "occasion" or "opportunity." An abuse of Christian freedom from slavery under the law could be a base of operations for the flesh, an opportunity for the "flesh" to launch a terribly destructive attack against us.
Paul uses the term flesh eight times in 5:13--6:10 to refer to that aspect of our being that is opposed to the Spirit of God (5:16-17) and that produces all that is evil and destructive in our human experience (5:19-20). The NIV translation of flesh as sinful nature is a helpful, interpretive translation. Human nature apart from God's intervening grace is both a captive of sin and the source of "passions and desires" (5:24) that lead to sin. No doubt one reason the Galatian Christians were attracted to the law is that they viewed the law as the only way to restrain and control the passions and desires of the flesh. They saw the law as a needed disciplinarian to keep them from being destroyed by their own sinful desires.
The law's restraining power over sinful desires is a common subject in Jewish literature and must certainly have been a theme in the campaign of the false teachers who were trying to bring the Gentile Christians under the law. We can imagine them saying, "How can you ever hope to win the battle against your evil desires? There is only one way. Come under the yoke of the law. The law was given to guard, protect and keep you from evil. Live under it as your master and guide." But now in contrast to this message of the false teachers, Paul says that he has "died to the law" (2:19), that "we are no longer under the supervision of the law" (3:25) and that we should not let ourselves "be burdened again by a yoke of slavery," by which he means the law (5:1). "Does this mean that we are free to follow the desires of our sinful nature?" the Galatians may have wondered. Paul, who was always sensitive to the questions in the minds of his readers, counters their misunderstanding with a strong prohibition: Do not use your freedom to indulge the sinful nature (v. 13).
I have interpreted this section of Paul's letter as his response to the possible misunderstanding of his gospel in contrast to the message of the law teachers. Others have interpreted this section as Paul's response to a "libertine group" in the church that advocated doing away with all restraints upon the flesh. In other words, they think Paul was fighting on two fronts: against the law teachers on one side and against the libertines on the other side. A somewhat different version of this "two-front" interpretation suggests that the Galatian converts were torn in two directions: by the message of the law teachers from the outside and by the libertine tendencies of their own Hellenistic culture. According to this interpretation, Paul wrote 1:6--5:12 against the threat of legalism (you are free from slavery under the law) and he wrote 5:13--6:10 against the threat of libertinism (you are not free to indulge your sinful nature).
But it seems better to interpret 5:13--6:10 as a continuation of Paul's argument against the law teachers for two reasons: First, Paul focuses on these law teachers immediately before (5:1-12) and after (6:11-14) this section. Second, this section constantly refers to the law (5:14, 18, 23; 6:2). So Paul is not aiming in a new direction in this section. It is still a response to people who wanted to live under the yoke of the law. They were hoping to be able to overcome their moral problems by concentrating on keeping the law. Paul seeks to convince them that the law has no power to restrain the flesh. On the contrary, those who try to overcome the sinful nature (the flesh) by observing the law become more deeply enslaved to the sinful nature (the flesh). Certainly Christian freedom from the law does not mean giving into the sinful nature. It means serving one another in love. And this is only possible by walking in the Spirit. That is the essence of Paul's ethical appeal. His appeal defines freedom as freedom to love (5:13-15), freedom by the Spirit (5:16-18), freedom from evil (5:19-21), freedom for moral transformation (5:22-26) and freedom to fulfill responsibilities (6:1-10).