(19) For there must be also heresies.--Better, For there must be also sects. There have been many attempts to explain where lies the difference between the "divisions" of the former verse and the "sects" of this verse. From all that we know of the Apostolic Church it is clear that neither of these words can mean sects separated from the Church, but "parties" in the Church. Christ had foretold (Matthew 18:7) that "stumbling-blocks," or "scandals," must arise in the Church, and it is possible that our Lord on some occasion spoke of these as "sects" (Justin Martyr attributes the use of this very word to our Lord); and St. Paul, possibly, uses the word here because it was the one traditionally reported as having been used by Christ in some of His unrecorded utterances. Christ has foretold that in the divine economy of permission such divisions will arise. They are allowed because this is a state of continual judgment; and the existence of such "offences" will be God's means of manifesting those who are void of offence, and those who are not.

Verse 19. - There must be also heresies among you. It results from the inevitable decrees of the Divine providence. "It is impossible but that offences will come" (Luke 17:11). Heresies. The word does not mean "erroneous opinions," but party factions. Originally the word only means "a choice," and is not used in a bad sense; but since the opinionativeness of men pushes "a choice" into a "party," and since it is the invariable tendency of a party to degenerate into a "faction," the word soon acquires a bad sense (see its use in Acts 5:17; Acts 15:5; Acts 24:5, 14: 28:22; Galatians 5:20; Titus 3:10; 2 Peter 2:1; and Gieseler, 'Church Hist.,' 1:149). The mutually railing factions, which in their Church newspapers and elsewhere bandy about their false and rival charges of "heresy," are illustrating the virulence of the very sin which they are professing to denounce - the sin of factiousness. That they which are approved may be made manifest among you. Similarly St. John (1 John 2:19) speaks of the aberrations of false teachers as destined to prove that they did not belong to the true Church. Good is educed out of seeming evil (James 1:3; 1 Peter 1:6, 7). Approved; standing the test (dokimoi), the opposite of the "reprobate" (adokimoi) of 1 Corinthians 9:27.

11:17-22 The apostle rebukes the disorders in their partaking of the Lord's supper. The ordinances of Christ, if they do not make us better, will be apt to make us worse. If the use of them does not mend, it will harden. Upon coming together, they fell into divisions, schisms. Christians may separate from each other's communion, yet be charitable one towards another; they may continue in the same communion, yet be uncharitable. This last is schism, rather than the former. There is a careless and irregular eating of the Lord's supper, which adds to guilt. Many rich Corinthians seem to have acted very wrong at the Lord's table, or at the love-feasts, which took place at the same time as the supper. The rich despised the poor, and ate and drank up the provisions they brought, before the poor were allowed to partake; thus some wanted, while others had more than enough. What should have been a bond of mutual love and affection, was made an instrument of discord and disunion. We should be careful that nothing in our behaviour at the Lord's table, appears to make light of that sacred institution. The Lord's supper is not now made an occasion for gluttony or revelling, but is it not often made the support of self-righteous pride, or a cloak for hypocrisy? Let us never rest in the outward forms of worship; but look to our hearts.For there must be also heresies among you.... This is a reason why he was ready to believe there might be something of truth in the report he had received of the divisions among them; for if there were heresies, false doctrines, and bad principles, among them, such as were subversive of the fundamentals of Christianity, as the denial of the resurrection of the dead, &c. it was no wonder that there were schisms and factions among them, since heresies generally issue in them. These, the apostle says, "must be"; because God has decreed they shall, whose counsel is immutable, and his purpose unalterable; and since this always was the case, that there were false prophets under the former dispensation, it must be expected that false teachers will arise in the churches now, bringing in damnable heresies; and since Satan is always busy to sow the tares of false doctrine; and human nature, being both weak and wicked, is so susceptible thereof, and so easily imposed upon and deceived, it cannot be thought that it should be otherwise; which, by the goodness and wisdom of God, are overruled to a very good purpose:

that they which are approved: who sincerely believe in Christ, are sound in the faith, and have a well grounded experience of it; who have themselves tried things that differ, and approve of them that are excellent, and have been tried by others, and found to be sincere, upright, and faithful, and are approved of God and good men:

may be made manifest among you; by their steadfastness in the faith, their zealous attachment to it, earnest contention for it, and warm and honest vindication of it; and by the departure of those from them who oppose it, and go on the side of error and heresy; by which means it is known who are the sincere followers of the Lamb, in doctrine, discipline, and conversation, and who not.