Pergamum was the official center of emperor worship in Asia Minor. It ranked second in importance amongst the seven cities and had a pantheon of deities. Thyatira, on the other hand, is a city of workers where guilds have flourished with the establishment of the Pax Romana (the Roman Peace).
Emperor worship was very active in Pergamum and Christians were faced with serious opposition and downright persecution. Christ tells the Christians of Pergamum that he knows where they dwell: where Satan's throne is. The Church in Pergamum is plagued with internal dissent and downright heretical teachings. Christ warns that unless they repent, He will come quickly and chastise them.
Guild members in Thyatira were required to offer a cult to the Emperor which is against the Christian faith. This left Christian workers in a bind for if they do not offer the Emperor a cult, they will not be able to join a guild and find a job; on the other hand, they cannot offer a cult to the Emperor without offending Christ.
As a result a certain woman, whom Christ calls Jezebel, proposed that it would be right for Christians to compromise, and this provokes the Lord's wrath. He will throw her on a bed of sickness and kill her children. To those who do not follow her, he places no other burden than to remain faithful.
What does it mean to "dwell where Satan's throne is?"
Who is this woman, Jezebel, and how relevant is she to our own time?
What is the relationship of all of this to the Council of Jerusalem?