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?

11. mouth … open unto you—I use no concealment, such as some at Corinth have insinuated (2Co 4:2). I use all freedom and openness of speech to you as to beloved friends. Hence he introduces here, "O Corinthians" (compare Php 4:15). The enlargement of his heart towards them (2Co 7:3) produced his openness of mouth, that is, his unreserved expression of his inmost feelings. As an unloving man is narrow in heart, so the apostle's heart is enlarged by love, so as to take in his converts at Corinth, not only with their graces, but with their many shortcomings (compare 1Ki 4:29; Ps 119:32; Isa 60:5).