The church at Pergamos was a good church in many ways. They had stayed faithful to Christ even though they were planted in Satan's backyard. They endured through persecution. They didn't deny Christ's name.

However, the danger of compromise had crept into this church. Pergamos was allowing the Nicolaitans to come in and teach that believers could live however they wanted to, embracing idolatry and immorality. Jesus speaks to warn them of allowing this compromise to remain in the church.