"Howbeit then, when ye knew not God, ye did service unto them which by nature are no gods. But now, after that ye have known God, or rather are known of God, how turn ye again to the weak and beggarly elements, whereunto ye desire again to be in bondage? Ye observe days, and months, and times and years."
The Galatian believers, who had formerly been pagans addicted to ritualistic worship, were being seduced by Jewish converts in the church to revert to a ceremonial, legalistic form of religion in place of knowing and obeying Christ from the heart.
These perverters of the truth were seeking to inculcate the ceremonial law at the church in Galatia. This ceremonial law---epitomised by circumcision (Galatians 5:2, 3, 6, 11; 6:15) and daily, monthly, and yearly observances--was prescribed by God in the law of Moses "until the time of reformation" (Hebrews 9:10), or the death of Christ on the cross (Galatians 4:10; Hebrews 9:8-12).
By compelling the Galatian converts to keep these obsolete laws, the Jewish Christians were effectually eclipsing Christ and His atoning work. They were utterly missing the fact that with His death on the cross, the Messiah would "cause the sacrifice and oblation [the ceremonial law, which foreshadowed the cross] to cease." Daniel 9:27. (See also Matthew 27:50, 51.) To practice the ceremonial law after Christ's death on Calvary was a virtual denial of His Messiahship and a betrayal of utter blindness to the significance of that law.