Here the apostle refers to some in the church at Galatia who were considering submitting to circumcision, having believed the Judaizers heretical doctrine that such "works" were necessary to bring their salvation in Christ to its proper and full consummation. If a person were to embrace this doctrine, says Paul, "Christ will be of no benefit" to him/her (v. 2). Furthermore, to submit to circumcision is to submit to the obligation "to keep the whole Law" (v. 3). Those who do this "have been severed from Christ" (v. 4). Those who seek to be justified by law "have fallen from grace" (v. 4).
The Arminian interpretation of this passage is that Paul envisions true Christians apostatizing from the faith and being cut off from the saving grace of God which they once genuinely experienced. They once were saved. Now they are lost.
The Calvinist alternative would recognize three possibilities.
First, some insist that these whom Paul describes are not, in point of fact, real Christians. They are professing believers who have identified externally with the church in Galatia (not an uncommon phenomenon in the first century, or any century). Their lack of true saving faith in Jesus is demonstrated by their desire to be justified in God's sight through works, circumcision in particular. Christ cannot be of any saving benefit to someone who refuses to submit to him and to the way of salvation he has ordained: by grace alone through faith alone. To seek justification by obedience to the law ("you who are seeking to be justified by law," v. 4) is to be cut off from the saving work of Christ. It is to fall from that principle of divine grace by which one may alone be saved. It is an issue of which way or path or means of acceptance with God you choose: grace or law. Such people fall "from grace" and "into legalism," not from salvation into condemnation. Advocates of this view would quickly point out the contrast Paul draws between people who pursue acceptance with God by such legal means and "we" (true believers), in v. 5, who "by faith" are waiting for the consummation of our salvation.
Second, others concede that those Paul describes are genuine Christians but that what they "lose" isn't salvation but the experiential blessings of intimacy with God that are grounded on and flow from the reliance of the soul on grace alone. Thus, being "severed" from Christ and falling "from grace" refer to the loss of joy, fellowship, reward, blessing, etc., but not the loss of one's place in the kingdom of God.
Third, the most likely interpretation is that Paul is addressing genuine, but immature, believers who, in the words of Demarest, were about "to defect from a theology of justification by grace to a theology of justification by law-keeping. They were running the race well until the Judaizers caused them to turn aside" (456). Paul has confidence "in the Lord," i.e., because of who Christ is and because of his commitment to his people, that "the erring saints would soon return to the truth" (v. 10) of the principle of justification by grace alone, through faith alone, in Christ alone (456). Gundry-Volf, on the other hand, believes that it is from more than a principle of grace that they stand to fall: it is from grace itself. In other words, they abandon and are severed from the very foundation of their salvation. But she agrees with Demarest that such will not, in point of face, ever happen. Paul's declaration of confidence in v. 10 is crucial to this understanding. Notwithstanding this severe warning (vv. 2-4), there Paul writes:
"I have confidence in you in the Lord, that you will adopt no other view; but the one who is disturbing you [a collective allusion to the Judaizers] shall bear his judgment, whoever he is."
"Paul not only hopes that his warnings and pleadings will evoke the desired response. He claims to 'have been persuaded in the Lord concerning you that you will think nothing other' than the truth (5:10). Though he anathematizes the perpetrators of the 'other gospel' (1:8,9) and consigns them to "judgment" (5:10), regarding them as 'false brethren' (cf. 2:4), he has confidence that his Galatian converts wil reaffirm their acceptance of the gospel he preached to them" (214).
The key to Paul's confidence is found in the words, "in the Lord"' In other words,
"after all Paul's efforts to mend the situation, he acknowledges that the Galatians' destiny does not lie in his hands but the Lord's. And the Lord's faithfulness guarantees the final outcome. . . . Paul's own intervention in the matter is not thereby rendered superfluous, however. For God's faithfulness can manifest itself precisely in the effect the apostle's warning and wooing has in the Galatian churches. . . . From the perspective of God's faithfulness, Paul is certain that the Galatians will not finally turn away from the gospel" (215).
Thus Paul envisions the faithfulness of God to his people as being greater and more powerful than the threat to their salvation. Paul's confidence is in the God who works and sustains and preserves in spite of human failure. As F. F. Bruce puts it, Paul "knows how the logic of the gospel works, and if they have really received the gospel (as he is convinced they have), they must accept the same logic and think no differently" (235).
In sum, the threat is real. True Christians are often tempted to turn away from the grace by which they are saved. To do so would be eternally disastrous. But God is faithful to sustain and preserve us. Therefore, in the words of the apostle Peter, we "are protected by the power of God through faith for a salvation ready to be revealed in the last time" (1 Peter 1:5). It is ultimately God's "power", not ours, that ever energizes and upholds our faith in Christ.