Though there has been some intervening material, Paul’s stance against those that are preaching a contrary gospel in Galatia (1:8), which he has referenced in the opening rebuke of chapter three, and which insists upon a reconstructing of dividing walls that have been torn down by the cross, is obviously very much in mind when he goes on to write “They court you eagerly, but for no good purpose; they want to exclude you, so that you would seek them eagerly” (4:17). Honor and shame considerations are very much at play here.
Judaizers and their presumably Jerusalem-backed supporters, that seek to continue divisions between Jew and Gentile and want to elevate the Jew over the Gentile even inside the church of Christ (wanting Gentiles to acknowledge the superiority of the Jew by their adherence to covenant markers), which we know must be present because of Paul’s recollection of his encounter with Peter in Antioch (attempting to force Gentiles to live like Jews – 2:14), want to use a lack of traditional covenant markers so as to exclude Gentiles from the covenant. In so doing, the Judaizers and Jews will be elevated in the eyes of the congregation, as having primacy in relation to the covenant, thus increasing their honor within the church and most likely their public honor outside of the church. Gentile openness to such things pains and perplexes Paul (4:19-20).
Ultimately, after relaying what he hopes is a useful allegory concerning slavery and freedom, contrasting the works of the law and belief in Jesus, he brazenly declares “For freedom Christ has set us free. Stand firm, then, and do not be subject again to the yoke of slavery. Listen! I, Paul, tell you that if you let yourselves be circumcised, Christ will be of no benefit to you at all” (5:1-2). Here, Paul echoes verse twenty-one of chapter two, where he wrote “I do not set aside God’s grace, because if righteousness,” or right standing in regards to the covenant (justification, salvation, etc…), “could come through the law, then Christ died for nothing!” These words are not to be heard apart from the Jew and Gentile divide and the issue of justification, and Paul’s assertion that “every man who lets himself be circumcised… is obligated to obey the whole law” (5:3), gains its import by being heard in correspondence with that issue.
At the same time, Paul is not going to let anybody get away with any half measures. If somebody wants to be identified as a covenant participant through the old covenant markers, thus rejecting the new covenant marker of belief in Jesus, then they must go all the way, observing Sabbaths and food laws (and perhaps even all of Torah). It feels as if Paul is reaching for the most persuasive terms possible, indicating the grave importance of Jesus alone (faith alone) as the covenant marker to be borne by the people of God as they continue their march of responsibility through history, representing a kingdom and a King.
This attempt at persuasion at all costs has Paul uttering things like “You who are trying to be declared righteous by the law have been alienated from Christ; you have fallen away from grace!” (5:4) The demand is clear: the kingdom of God and its covenant will be realized through God’s gracious demonstration of Himself through Jesus the Christ. Though it used to be the case that those that did not live in accordance with the covenant markers of Israel were the ones that were aliens to the covenant, now it is the case that those who live according to those covenant markers are, in fact, the ones who are aliens to the promise. There is no going back. “In Christ Jesus neither circumcision nor uncircumcision carries any weight---the only thing that matters is faith working through love” (5:6).