Revelation 2:20 “Nevertheless I have a few things against you, because you allow that woman Jezebel, who calls herself a prophetess, to teach and seduce My servants to commit sexual immorality and eat things sacrificed to idols.
There is a distinct similarity here in what Thyatira is experiencing and what Pergamos likewise experienced, Revelation 2:14. In Pergamos this was referred to as the doctrine of Balaam. Balaam, a false prophet (perhaps formerly a true prophet?) taught Balak and Moab to seduce Israel by sexual immorality and idolatry.