Christ’s words in Revelation 2:12-17, is addressed to the locally assembled church in the geographic place called Pergamum: a place of Satan’s seat. There we have heard Christ’s words, which contain a warning about idolatry, Satan’s plan of false worship.
From those early days after Creation, when Adam sinned and all of mankind to follow also fell into sin, God made a way for mankind to come back. The way back was to worship Him by a substitutionary, sacrificial, blood-sprinkled way.
The key to understanding all of world history since the Fall of Humanity into sin comes from God’s Word. Always remember that the only absolutely trustworthy and accurate account of the earliest days of both the Universe and the human race is found in the inspired words from God in Genesis.