14 Don't become partners with those who reject God. How can you make a partnership out of right and wrong? That's not partnership; that's war. Is light best friends with dark? 15 Does Christ go strolling with the Devil? Do trust and mistrust hold hands? 16 Who would think of setting up pagan idols in God's holy Temple? But that is exactly what we are, each of us a temple in whom God lives. God himself put it this way: "I'll live in them, move into them; I'll be their God and they'll be my people. 17 So leave the corruption and compromise; leave it for good," says God. "Don't link up with those who will pollute you. I want you all for myself. 18 I'll be a Father to you; you'll be sons and daughters to me."
Matthew Henry's Commentary on 2 Corinthians 6:14-18
Commentary on 2 Corinthians 6:11-18
(Read 2 Corinthians 6:11-18)
It is wrong for believers to join with the wicked and profane. The word unbeliever applies to all destitute of true faith. True pastors will caution their beloved children in the gospel, not to be unequally yoked. The fatal effects of neglecting Scripture precepts as to marriages clearly appear. Instead of a help meet, the union brings a snare. Those whose cross it is to be unequally united, without their wilful fault, may expect consolation under it; but when believers enter into such unions, against the express warnings of God's word, they must expect must distress. The caution also extends to common conversation. We should not join in friendship and acquaintance with wicked men and unbelievers. Though we cannot wholly avoid seeing and hearing, and being with such, yet we should never choose them for friends. We must not defile ourselves by converse with those who defile themselves with sin. Come out from the workers of iniquity, and separate from their vain and sinful pleasures and pursuits; from all conformity to the corruptions of this present evil world. If it be an envied privilege to be the son or daughter of an earthly prince, who can express the dignity and happiness of being sons and daughters of the Almighty?