1 Corinthians 11:17-19 ESV
But in the following instructions I do not commend you, because when you come together it is not for the better but for the worse. For, in the first place, when you come together as a church, I hear that there are divisions among you. And I believe it in part, for there must be factions among you in order that those who are genuine among you may be recognized.
ESV: English Standard Version 2016