In Second Corinthians 6, Paul exhorted the brethren not to be unequally yoked with unbelievers. The unbelievers he had reference to in that passage were not just those who did not believe in the one God and Father of all, they were idol worshippers. The apostle instructs them that the righteous have no fellowship with the unrighteous, light has no communion with darkness, that there is no agreement between Christ and Belial, and the believer has no part with the infidel. Those things being the case, there is no agreement between the temple of God and the temple of idols. The conclusion was that the Corinthians were to come out from among those unbelievers.
Not only were the Corinthian brethren to come out from among “them,” they were to be so separate that they did not even touch the unclean thing. These commands were given with promises if they were kept. God promised to dwell in them and they would be His sons and daughters. In the first verse, then, of chapter seven, Paul tells them that since they had those conditional promises they were to cleanse themselves from all filthiness of the flesh.
Today, Christians still live in a world filled with unbelievers. There is filthiness in the world today just as there was in the days of the apostles. Some of that filthiness is still in the form of idolatry, as it was in the first century. Some of the filthiness in the world today are the same wicked things that were associated with the idolatrous worship that Paul confronted in Corinth and other cities on his missionary journeys. That filth certainly includes sins of sexual wickedness, and other things just as evil.
Christians today, live in a world over run by drunkenness, lying, greed, murder, (including abortions), homosexuality, covetousness (which is idolatry), and the list goes on and on.
Just as the promises that Paul says that God would keep to the Corinthians were conditional, we have those same promises with the same conditions today. Christians cannot take part in wickedness and have God dwelling in them. Just as the Corinthians were not to touch the unclean thing, neither are we. Those who refuse to separate themselves from the world will be cast off eternally in the day of judgment (Rev. 21:8). That is why the New Testament is full of warnings for us: have no fellowship with the unfruitful works of darkness (Eph. 5:11), stay away from all appearance of evil (1 Thess. 5:22), and don’t use our liberty as a cloak for maliciousness (1 Pet. 2:16), to name only a few.
“Wherefore come out from among them, and be ye separate, saith the Lord, and touch not the unclean thing; and I will receive you, and will be a Father unto you, and ye shall be my sons and daughters, saith the Lord Almighty” (2 Cor. 6:17-18).