We then, as workers together with him - On the meaning of this expression, see the note, 1 Corinthians 3:9. The Greek here is (συνεργοῦντες sunergountes) “working together,” and may mean either that the apostles and ministers to whom Paul refers were joint-laborers in entreating them not to receive the grace of God in vain; or it may mean that they cooperated with God, or were engaged with him in endeavoring to secure the reconciliation of the world to himself. Tyndale renders it: “we as helpers.” Doddridge, “we then as the joint-laborers of God.” Most expositors have concurred in this interpretation. The word properly means, to work together; to cooperate in producing any result. Macknight supposes that the word here is in the vocative, and is an address to the fellow-laborers of Paul, entreating them not to receive the grace of God in vain. In this opinion he is probably alone, and has manifestly departed from the scope and design of the passage. Probably the most obvious meaning is that of our translators, who regard it as teaching that Paul was a joint-worker with God in securing the salvation of people.
That ye receive not the grace of God in vain - The “grace of God” here means evidently the gracious offer of reconciliation and pardon. And the sense is, “We entreat you not to neglect or slight this offer of pardon, so as to lose the benefit of it, and be lost. It is offered freely and fully. It may be partaken of by all, and all may be saved. But it may also be slighted, and all the benefits of it will then be lost.” The sense is, that it was possible that this offer might be made to them, they might hear of a Saviour, be told of the plan of reconciliation and have the offers of mercy pressed on their attention and acceptance, and yet all be in vain. They might notwithstanding all this be lost, for simply to hear of the plan of salvation or the offers of mercy, will no more save a sinner than to hear of medicine will save the sick. It must be embraced and applied, or it will be in vain. It is true that Paul probably addressed this to those who were professors of religion; and the sense is, that they should use all possible care and anxiety lest these offers should have been made in vain. They should examine their own hearts; they should inquire into their own condition; they should guard against self-deception. The same persons 2 Corinthians 5:20 Paul had exhorted also to be reconciled to God; and the idea is, that he would earnestly entreat even professors of religion to give all diligence to secure an interest in the saving mercy of the gospel, and to guard against the possibility of being self-deceived and ruined.