Jesus warned the assembly in Pergamos, Therefore, repent: but if not, I am coming to you quickly, and I will do battle with them with the sword in My mouth.
Revelation 2: Pergamos
if the Ephesian Christians had subtly replaced their love for God and each other with a love for righteousness and right doctrine, the Pergamenian Christians had subtly allowed the erosion of right doctrine in their own midst, while they still held to their faith and trust in Christ.