I Corinthians 5:9

I wrote . . . in an epistle--rather, "in the Epistle": a former one not now extant. That Paul does not refer to the present letter is proved by the fact that no direction "not to company with fornicators" occurs in the previous part of it; also the words, "in an (or, the) epistle," could not have been added if he meant, "I have just written" (Co2 10:10). "His letters" (plural; not applying to merely one) confirm this. Co2 7:8 also refers to our first Epistle, just as here a former letter is referred to by the same phrase. Paul probably wrote a former brief reply to inquiries of the Corinthians: our first Epistle, as it enters more fully into the same subject, has superseded the former, which the Holy Spirit did not design for the guidance of the Church in general, and which therefore has not been preserved. See my Introduction.

Here the apostle advises them to shun the company and converse of scandalous professors. Consider, I. The advice itself: I wrote to you in a letter not to company with fornicators, Co1 5:9. Some think this was an epistle written to them before, which is lost. Yet we have lost nothing by it, the Christian revelation being entire in those books of scripture which have come down to us, which are all that were intended by God for the general use of Christians, or he could and would in his providence have preserved more of the writings of inspired men. Some think it is to be understood of this very epistle, that he had written this advice before he had full information of their whole case, but thought it needful now to be more particular. And therefore on this occasion he tells them that if any man called a brother, any one professing Christianity, and being a member of a Christian church, were a fornicator, or covetous, or an idolater, or a railer, that they should not keep company with him, nor so much as eat with such a one. They were to avoid all familiarity with him; they were to have no commerce with him; they were to have no commerce with him: but, that they might shame him, and bring him to repentance, must disclaim and shun him. Note, Christians are to avoid the familiar conversation of fellow-christians that are notoriously wicked, and under just censure for their flagitious practices. Such disgrace the Christian name. They may call themselves brethren in Christ, but they are not Christian brethren. They are only fit companions for the brethren in iniquity; and to such company they should be left, till they mend their ways and doings. II. How he limits this advice. He does not forbid the Christians the like commerce with scandalously wicked heathens. He does not fo…

5:9-13 The church is to discipline anyone in the church who is known to be living in sin. 5:9 When I wrote to you before refers to an earlier letter now lost. • Sexual sin is any form of illicit sexual activity (see also 6:9).