I Corinthians 11:19 For there must be also heresies among you, that they which are approved may be made manifest among you.
The word heresy refers to a fundamental error in doctrine. It would usually refer to a denial of essential Biblical doctrine.
The basic word refers to division. It would speak of a group holding to certain beliefs. It is used in the Bible to talk about the sect of the Sadducees or Pharisees. The word refers to dissension or groups thinking a certain way.
A church was supposed to be a coming together of one body. In other words, they weren’t supposed to be divided into disagreeing groups or factions. These factions would be caused by a comprise in doctrine or holiness.
These heresies or divisions were good because it would allow them to see who believed and who didn’t. Trouble, fighting, and fussing would only separate out the compromised and less committed.
Ours is not to get along and be friends but to stand for the truth and let those who do not have the same commitment leave. Stand for truth so that it is obvious you are doing right.