If you listen to a false teacher enough, you will discover what Peter revealed about them, “But these, like natural brute beasts made to be caught and destroyed, speak evil of the things they do not understand… (2 Peter 2:12).
Peter spoke strongly against false teachers, but he had seen the damage they do to the church, how they tear apart a good work that a preacher, such as Peter, had given his entire self to establish.
False teachers would speak evil of things they do not fully understand. They do not understand something, so they speak evil of it, instead of trying to understand it. They do not like to open their minds to the truth about people or good works, believing they already know enough, but they just show their own foolishness.