Paul gives a command, "Be ye not unequally yoked together with unbelievers," and then backs it with two questions. Each one sets two things side by side that cannot share life together: righteousness and unrighteousness, light and darkness. The questions press the Corinthians to see for themselves that such a partnership makes no sense. Barnes ties this to the verse before: one way the Corinthians could repay Paul's love was to obey him and separate from improper alliances with unbelievers. Gill calls these questions reasons meant to move believers to heed the command.

Paul does not stop for an answer, because it is obvious: none. He adds more questions of the same kind (2 Corinthians 6:15-16), then reminds them, "ye are the temple of the living God" (2 Corinthians 6:16). He calls them to "come out from among them, and be ye separate" (2 Corinthians 6:17), with God's promise, "I ... will be a Father unto you" (2 Corinthians 6:17-18). He sums it up: "let us cleanse ourselves from all filthiness of the flesh and spirit, perfecting holiness in the fear of God" (2 Corinthians 7:1).

"Unequally yoked" translates one Greek word, heterozugeo, which Barnes explains means "to bear a different yoke," like two different kinds of animals put under one yoke. Gill suggests this "seems to be an allusion" to the law of Moses: "Thou shalt not plow with an ox and an ass together" (Deuteronomy 22:10). In the two questions, "fellowship" is the Greek metoche (sharing, partnership) and "communion" is koinonia (fellowship, having in common). Barnes notes that many commentators have applied this verse to marriage; he says it includes marriage but should not be limited to it. Gill disagrees that the verse is about marriage, though he says believers would do well to avoid such a match; he reads it as a general warning against joining unbelievers in anything sinful.

These questions grow out of who believers are. Paul is not describing two teams that happen to disagree. He is naming things that are opposite by nature: righteousness and unrighteousness, light and darkness. Barnes says the difference between believers and unbelievers is so great "that it is as improper for them to mingle together as it is to yoke animals of different kinds and species."

Yet this is not a call to leave the world. Gill is clear that Paul is not forbidding ordinary dealings with unbelievers, since otherwise believers would have to leave the world, as Paul had said before (1 Corinthians 5:10). The warning is against binding partnerships that pull a believer under a different yoke. And the call comes wrapped in love: Paul has just opened his heart to them (2 Corinthians 6:11-13), and God's promise follows (2 Corinthians 6:16-18).