The first signpost issues a harsh warning to all who rely on observing the law. They are under a curse. The warning is based on a quotation from the law itself: Cursed is everyone who does not continue to do everything written in the Book of the Law (see Deut 27:26). In Deuteronomy a long list of terrible curses concludes with severe warnings of complete destruction (Deut 30:11-20). Since the curse is the result of failure to do the law, it must be assumed by Paul that all who rely on observing the law fail to do the law. In fact, Paul explicitly asserts at the end of his letter that "not even those who are circumcised obey the law" (6:13).

In the context of the Galatian dispute, when Paul refers to all who rely on observing the law he is speaking about those who are persuading the Galatian believers to enter their circle by keeping the law. Paul seems especially concerned to prove to the Galatians that the very ones who are inviting them to join the group of lawkeepers are under a curse, since they actually are lawbreakers. If the lawkeepers themselves are under a curse for having failed to keep all the law, then the risk of incurring a curse is even greater for Gentile believers who accept only certain items of the law in order to identify with the Jewish nation. An acceptance of requirements such as circumcision and sabbath keeping obligates them to keep the whole law (5:3). And if all who rely on observing the law cannot keep the whole law (see 2:14 and 6:13), then surely the Galatian believers will not be able to do so either. Hence they will surely come under a terrible curse for failure to keep the whole law. Paul points to this curse to dissuade Galatian believers from seeking membership among those who rely on observing the law and so placing themselves under the curse of the law.

If you join a group known for untainted fundamentalism and uncompromising separatism in order to be sure of God's blessing, beware! Since no one, not even the most saintly, ever kept the whole law, even the members of this group are under a curse for failure to keep the whole law.