2 Corinthians 6:1

Since God appeals to the unsaved through heralds of the gospel (2 Corinthians 5:20), the herald is in that sense a partner with God in His work of bringing people into final reconciliation. Another less likely view is that Paul meant that he labored together with the Corinthians (cf. 2 Corinthians 5:20; 1 Corinthians 3:9). The words "with Him" are not in the Greek text. In this case the objects of their entreaty would be the unsaved. Evangelism is a joint effort of the Lord and His human ambassador. Paul went beyond that specific function of an ambassador and, for God, also appealed to his Christian readers. In addition to responding to the call to be reconciled to God, they also needed to respond to another call. They needed to make sure that they were responding to God’s grace as well.

Paul’s readers had received God’s grace when they had heard the gospel message. Now Paul urged them to respond to it so God’s gracious bestowal would not have been in vain. God gives grace to all people throughout their lives, but He gives more grace at the moment of conversion and from then on. It is not clear which manifestation of grace Paul had in mind, the grace the Corinthians received at conversion or the subsequent grace. I think he probably had both in mind and spoke of their response to divine grace generally since he did not clearly identify the past or the present manifestation. Receiving God’s grace in vain would be not allowing it to have its divinely intended result in their lives. Paul occasionally wrote of receiving God’s grace in vain, by which he meant failing to persevere (cf. 1 Corinthians 15:2; 1 Corinthians 15:10; Galatians 4:11; Philippians 2:16). In the context, conflict between some of the Corinthians and Paul resulting in the discrediting of the gospel ministry seems to be in view (2 Corinthians 6:3). More generally, disunity among believers frustrates God’s desire and His provision of grace (help). Most broadly, any disobedience to God’s will frustrates His grace (cf. 2 Corinthians 7:1; 2 Corinthians 11:4; 2 Corinthians 12:20-21).

"The explanation which in our judgment is most satisfactory, and which seems best to fit the broad context in which this verse is found, is that Paul is here thinking in terms of the judgment-seat of Christ, before which the works of every Christian will be made manifest (2 Corinthians 5:10)." [Note: Hughes, p. 218. Cf. Martin, p. 166.]