1 Corinthians 5:12

Next he adds also the reason why he forbids them not to mix with heathens of that character, implying that it is not only impossible, but also superfluous. "For what have I to do with judging them that are without?" Calling the Christians and the Greeks, "those within" and "those without," as also he says elsewhere, "He must also have a good report of them that are without." And in the Epistle to the Thessalonians he speaks the same language, saying, "Have no intercourse with him to the end that he may be put to shame." And, "Count him not as an enemy, but admonish him as a brother." Here, however, he does not add the reason. Why? Because in the other case he wished to soothe them, but in this, not so. For the fault in this case and in that was not the same, but in the Thessalonians it was less. For there he is reproving indolence; but here fornication and other most grievous sins. And if any one wished to go over to the Greeks, he hinders not him from eating with such persons; this too for the same reason. So also do we act; for our children and our brethren we leave nothing undone, but of strangers we do not make much account. How then? Did not Paul care for them that were without as well? Yes, he cared for them; but it was not till after they received the Gospel and he had made them subject to the doctrine of Christ, that he laid down laws for them. But so long as they despised, it was superfluous to speak the precepts of Christ to those who knew not Christ Himself. "Do not ye judge them that are within, whereas them that are without, God judgeth?" For since he had said, "What have I to do with judging those without;" lest any one should think that these were left unpunished, there is another tribunal which he sets over them, and that a fearful one. And this he said, both to terrify those, and to console these; intimating also that this punishment which is for a season snatches them away from that which is undying and perpetual.