1 Corinthians 3:9
9. Translate, as the Greek collocation of words, and the emphasis on "God" thrice repeated, requires, "For (in proof that "each shall receive reward according to his own labor," namely, from God) it is of God that we are the fellow workers (laboring with, but under, and belonging to Him as His servants, 2Co 5:20; 6:1; compare Ac 15:4; see on 1Th 3:2) of God that ye are the field (or tillage), of God that ye are the building" [ALFORD]. "Building" is a new image introduced here, as suited better than that of husbandry, to set forth the different kinds of teaching and their results, which he is now about to discuss. "To edify" or "build up" the Church of Christ is similarly used (Eph 2:21, 22; 4:29).
2 Corinthians 6:1
1. workers together—with God (Ac 15:4; 1Co 3:9). Not only as "ambassadors."
beseech—entreat (2Co 5:20). He is describing his ministry, not exhorting directly. you also—rather, "WE ALSO (as well as God, 2Co 5:20) beseech" or "entreat you": 2Co 6:14, 15, on to 2Co 7:1, is part of this entreaty or exhortation. in vain—by making the grace of God a ground for continuance in sin (2Co 6:3). By a life of sin, showing that the word of reconciliation has been in vain, so far as you are concerned (Heb 12:15; Jude 4). "The grace of God" here, is "the reconciliation" provided by God's love (2Co 5:18, 19; compare Ga 2:2).