Summary: In Galatians 5:13b-15, Paul gives four purposes of God’s call to the freedom of loving Him: 1) To oppose the flesh (GALATIANS 5:13B), 2) To serve others (GALATIANS 5:13B), 3) To fulfill His moral law (GALATIANS 5:14), and 4) To avoid harming others (GALATIANS 5:15).
Recently, a labour arbitrator has ruled that the municipality of Waterloo will have to rehire a drug-addicted nurse who stole narcotics and falsified medical records. The crux of this ruling was that the municipality, as an employer, has a duty to accommodate the wayward nurse’s disease of drug addiction. The Arbitrator ruled that it was discriminatory to fire her, even through she had betrayed the most fundamental and explicit obligations of her profession. The theft and the faked paperwork were declared as symptoms, and ought to have been treated as such. (https://nationalpost.com/opinion/colby-cosh-the-big-problem-with-addiction-is-a-disease)
Ours is a day of addiction, not only to alcohol and drugs but also to sexual passions, violence, and many other forms of bondage in which entrap. When people choose to persist in a sin, they develop less and less control over it until eventually they forfeit any choice entirely. When people get to the point of addiction, they cannot successfully control their sinful thoughts and actions even when they may want to. And ironically, the more one asserts a self-centered false freedom, the more one becomes enslaved to sin.
Paul has already spoken of the “liberty which we have in Christ Jesus” (Gal. 2:4) and presented an analogy illustrating the believer’s spiritual descent from Abraham’s wife Sarah, a “free woman” (Gal. 4:21–31). He now declares:
Galatians 5:13a  For you were called to freedom, brothers. (Only do not use your freedom as an opportunity for the flesh, but through love serve one another). (ESV)
Freedom is at the very heart of the gospel and of godly living. It is not a side benefit or an adjunct to the Christian life. God has called all believers to freedom. To what are we called: we are called to liberty. The Christian is free. Free from the guilt of sin because the believer has experienced God’s forgiveness. The believer is free from the penalty of sin because Christ died for the believer on the cross. And the believer is, through the Spirit, free from the power of sin in daily life. The believer is also free from the Law with its demands and threats. (One day, when believers get to glory, we will be free from the presence of sin. (Wiersbe, Warren W.: The Bible Exposition Commentary. Wheaton, Ill. : Victor Books, 1996, c1989, S. Ga 5:13)
Believers have “Freedom in Christ” . In Galatians 5:13b-15, Paul gives four purposes of God’s call to the freedom of loving Him: 1) To oppose the flesh (GALATIANS 5:13B), 2) To serve others (GALATIANS 5:13B), 3) To fulfill His moral law (GALATIANS 5:14), and 4) To avoid harming others (GALATIANS 5:15).
Believers have “Freedom in Christ” in order:
1) To Oppose the Flesh (Galatians 5:13b)
Galatians 5:13b  (For you were called to freedom, brothers). Only do not use your freedom as an opportunity for the flesh, (but through love serve one another). (ESV)
The Judaizers, and some of the immature Jewish believers, considered Paul to be antinomian, a lawless libertine. Because the opposite extremes of legalism and antinomianism are both human-centered, they have always been attractive to sinners. The legalist satisfies himself, and presumably God, by adhering to a strict external code of do’s and don’ts, which they imagine demonstrate their self-righteous suitability for heaven. The antinomian, on the other hand, satisfies themselves by rejecting all codes and living completely according to their personal lusts and desires. Whereas legalism demands responsibility without freedom, license grants freedom without responsibility (Philip Graham Ryken: Galatians: Reformed Expository Commentary. P&R Press. 2005. p. 217).
Paul makes clear that the freedom of the gospel is not tolerance of self-indulgence. It is not a means for satisfying the desires of the flesh but for opposing them. That is why he warned: “do not use your freedom as an opportunity for the flesh,”. Aphorme (opportunity) was often used to indicate a central base from which all operations of a military campaign originated. In this context flesh (sarx/s???) does not refer to the physical body but to the sinful inclination of fallen humanity, the old self, whose supreme desire is to do its own will and to satisfy its sinful appetites. It is a synonym for sinful self-will. Paul’s declaration is that Christian freedom is not a base of operations from which the flesh is given opportunity to carry on its campaigns of sin freely and without consequence. If unchecked, the ‘flesh’ produces the ‘works of the flesh’ listed in vv 19f (Bruce, F. F. (1982). The Epistle to the Galatians: a commentary on the Greek text (p. 240). Grand Rapids, MI: W.B. Eerdmans Pub. Co.).
Christ does not give freedom to believers so they can do what they want but so they can, for the first time, do what God wants, because of love for Him. Within the bounds of their particular situations and abilities, even the most ungodly unbelievers are already free to do what they themselves want to do. They have more than ample opportunity to indulge the desires of the flesh, and it was hardly necessary for Christ to provide that sort of liberty. But Paul’s point is immeasurably more important than that obvious truth. The great reality he declares here is that it is freedom from sin, represented by the flesh, that the gospel saves believers. Whatever Christian freedom is, it is clearly not the right of believers to return to that from which Christ paid with His own life to save them. That is why Peter said: