Christians have a tendency to label anyone a false teacher who does not agree with them, but the Bible shows the characteristics of a false teacher in Second Peter 2.
Notice the second half of verse 13 and verse 14,
“They are spots and blemishes, carousing in their own deceptions while they feast with you, having eyes full of adultery and that cannot cease from sin, enticing unstable souls. They have a heart trained in covetous practices, and are accursed children” (2 Peter 2:13–14).
Watch out for these people, for they will not appear as evil, but Peter spoke of “their own deceptions.” Therefore, a false teacher is not someone with whom we disagree on the understanding of Scripture, but a false teacher has evil in his heart and desires to pull away members from the body of Christ to start his own group.