The cross is the center of God's operation in His economy. In this Epistle Paul was bringing the believers who had been distracted to the law back to the cross and encouraging them to behold Christ crucified, that they would never again be distracted to the law. This Epistle provides a thorough view of Christ crucified (Gal. 1:4; 2:19-21; 3:13; 5:24; 6:14).
The crucifixion of Christ indicates that all the requirements of the law have been fulfilled by the death of Christ, and that Christ through His death has released His life that it may be imparted into us in His resurrection to free us from bondage under the law. This was fully portrayed before the eyes of the Galatians in the word of the gospel. How could they neglect this and be bewitched, drifting back to the law? How foolish!