(Galatians 5:1). [Amplified Bible].
A. Summary and Transition (5:1)
Paul has already reached two important goals in his appeal to the Galatians. He has defended his apostleship, including a defense of his right to preach the Gospel with or without the support of other human authorities (Galatians 1:11-2:21), and he has defended the Gospel itself, showing that it is bt grace alone, apart from human works, and that the Christian is freed from the curse of the law and brought into a right relationship with God (Galatians 3:1-4:31). But Paul must make one more point before he concludes his letter: that liberty into which believers are called is not a liberty that leads to license, as his opponents charged, but rather a liberty that leads to mature responsibility and holiness before God through the power of the indwelling Holy Spirit. This theme dominates his last two chapters.
5:1 Before plunging into this third section of his letter, Paul interjects a verse that both summarizes all that has gone before and serves as a transition to what follows. It is, in fact, the key verse of the entire letter. Because of the nature of the true Gospel and of the work of Christ on their behalf, believers must now turn away from anything that smacks of legalism and instead rest in Christ's triumphant work for them and live in the power of the Spirit. The first part of this verse aptly sums up the message of chapters 3-4, while the second part leads into the ethical section. Paul appeals for an obstinate perserverance in freedom as the only proper response to any attempt to bring Christians once more under legalism.
Since the Jews of Paul's time spoke of taking the yoke of the law upon themselves, Paul probably alludes to such an expression here. To the Jews taking up the law's yoke was the essence of religion; to Paul it was assuming the yoke of slavery. He must also be remebering Jesus' reference to Christians taking his yoke upon them (Matthew 11:29-30), but his yoke was "easy" and "light."
[NIV BIBLE COMMENTARY Volume 2: New Testament].
JESUS IS LORD.