1 Corinthians 11:19 - Ellicott's Commentary On The Whole Bible

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.