https://preachitteachit.org/articles/detail/what-is-satans-throne-in-revelation/

"Why does Jesus call Pergamum’s church the place where Satan’s throne is?

Revelation 3:12 “And to the angel of the church in Pergamum write: ‘The words of him who has the sharp two-edged sword.

13 “‘I know where you dwell, where Satan’s throne is.

Pergamum was a city that prided itself on several temples dedicated to the Roman Imperial cult.

In the Roman period, the city of Pergamum, a former administrative capital of Asia Minor that later was moved to Ephesus, became a flag ship for Roman patriotism expressed in religious devotion.

As with most major Greek cities, Pergamum boasted a theater, stadium, library and a healing center of Asclepius among the other buildings that were part of normal life in the Greco-Roman world.

Pergamum’s citizens were zealous, wealthy and well-educated. They were not to be trifled with.

Satan appears as an angel of light. He rules the world, according to Luke 4. His presence in Pergamum reflected His seductive, dangerous influence.

The healing center (Asclepion) in Pergamum, was the headquarters for a very large network of healing centers throughout the Roman Empire. For many years Galen, the most well-known physician in the Roman Empire and personal physician of Emperor Marcus Aurelius, worked there.

The Pergamum library was considered second only to the world-famous library in Alexandra. The Pergamum library boasted, according to Plutarch, more than 200,000 volumes. Another account states that Marc Anthony, a Roman military commander, bequeathed the collection to Cleopatra as a reimbursement for the total destruction of the library of Alexandria’s by Julius Caesar.

Pergamum held the high honor of hosting and maintaining a temple to Zeus – Father of all gods and man and the ruler of Olympians on Mt. Olympia in accordance with ancient Greek beliefs.

Zeus was closely associated with the Roman deity Jupiter whose name means the sky or literally the “heavenly father” god.

The altar to Zeus was one of the most impressive structures in Pergamum. The altar’s stairs, columns, and sculptured sides once stood forty feet (12 meters) high.

Today, only the steps around the altar’s base can be seen in the Pergamum museum in Berlin. The sides of the altar were ornamented with marble panels depicting a mythical battle between Greek gods and rebellious giants who were the sons of Mother Earth.

Many have suggested that this altar to Zeus is what is meant by the throne of Satan in vs. 13.

But there exist a number of other possibilities – such as the Asclepius cult headquarters or a concentration of the Imperial and Roman cult in that city.

In Roman antiquity, the image of a sword and especially a double-edged sword was highly symbolic. So, in this city, it can truly be said that it hosted the throne of Satan, the symbol of Roman Imperial authority and rule.

Christ introduced himself to the assembly of the follows of Israel’s God in Christ as “the one who has the sharp two-edged sword.” If the above identification of the throne of Satan as Roman imperial cult is correct than it would make a perfect sense for Christ here to be presented as someone with the authority of the double-edged sword.

“Yet you hold fast my name, and you did not deny my faith even in the days of Antipas my faithful witness, who was killed among you, where Satan dwells.”

Christian tradition holds that Antipas was ordained as the bishop of Pergamum by the Apostle John, just as was Polycarp in the city of Smyrna. The tradition also holds that he was boiled alive in a bronze kettle that resembled a bull.

Christ called the assembly in Pergamum that tolerated in its mix those who both professed Christ and ate meat sacrificed to Roman gods, to repent. Christ the King threatened them with his soon-approaching judgment, calling them to finally make a choice between the God of Israel and the gods of the Roman Empire."