What does Paul mean when he refers to the possibility of receiving the grace of God "in vain"? See also Gal. 2:2; Phil. 2:16; 1 Thess. 3:5 (cf. 1 Cor. 15:2). Some suggested answers:
1. Perhaps he is urging them not to forfeit the grace of salvation which they had earlier received. In other words, it is an exhortation to persevere, to avoid apostasy. On this view, Paul would be implying that a born-again believer can lose or forfeit his/her salvation.
2. Some suggest the exhortation in vv. 1-2 is not directed to those Corinthians who are already born-again, but to those in Corinth who had repeatedly heard the gospel but had made no decision. Paul was not so naive to think that everyone in the professing church was necessarily truly converted. Therefore, his command not to receive the grace of God in vain is equivalent to an exhortation to all men not to reject the gospel of Jesus Christ. But is "to receive in vain" really the same as "reject"?
3. God's grace may be received in vain when it is received superficially or externally, as in the parable of the soils (Luke 8:4-15; Matt. 13:18-23). There the seed (gospel) falls upon rocky ground or among thorns, to be snatched away or choked by the temptations of this world. This view is similar to the previous one, insofar as the people in view are unbelievers. The difference is that, according to this interpretation, people don?t explicitly reject the gospel but ?receive? and ?believe? it, but only in a superficial way. Their so-called ?faith? is spurious and therefore temporary.
4. Perhaps receiving the grace of God in vain pertains not so much to salvation per se, or its forfeiture, but to the loss of potential blessings related to spiritual growth, knowledge, and joy that they would suffer by rejecting Paul as their apostle. In other words, the people are truly saved. They have genuinely received the gospel and believed it, but they have failed to progress in their Christian growth and stand in danger of losing those spiritual blessings and rewards they otherwise might have obtained.
5. Philip Hughes suggests that "for them to receive the grace of God in vain meant that their practice did not measure up to their profession as Christians, that their lives were so inconsistent as to constitute a denial of the logical implications of the gospel, namely, and in particular, that Christ died for them so that they might no longer live to themselves but to His glory" (218-19). In other words, the passionate conviction which accompanied their salvation had not as yet performed its transforming work in their lives. It is to that progressive transformation of their daily experience that Paul is urging and exhorting them. In the final analysis, this view differs very little from number 4.
6. Judith Gundry-Volf suggests that to receive the grace of God in vain may be referring to their opposition to the apostle himself. The context surrounding this statement is Paul's description of his ministry on their behalf and his attempt to restore good relations with the Corinthians (5:13-14; 5:18-6:1; see especially his impassioned appeal in 6:11-13). In Paul's opinion, to reject him is to reject the gospel of salvation of which he is a minister. If the Corinthians receive the grace of God in vain, it is not because of ethical/moral failure/rebellion, but rather rejection of the gospel as a consequence of rejection of the apostle and the apostolic message. Gundry-Volf then argues that Paul's appeal is simply "for the sake of argument only" (280). I.e., he does not believe they will reject or deny him, but if they were to do so it would be tantamount to receiving the grace of God, which was his message to them, in vain.