Explaining The Book of The Revelation of Jesus Christ - The letter to The Church in Pergamom

There were two levels of compromise that happened. The first was that the Jews assimilated with the greeks and adopted greek culture including names and this then led to the second compromise was syncretism which was that pagan beliefs infiltrated the church.
When christians needed healing, they would go to hospitals but all hospitals where infused deeply with pagan practices and if the doctor could not heal them, they would send them to pagan healing centers where they would induce dream sleep in the belief that healing would come through the gods as a pagan priest recited words down to them. Basically, paganism was inescapable
Christians also had to buy meat in the mainstream retailers that had been sacrificed to idols in the temples
Major shifts began under the authority of Emperor Constantine. Even if there were many who had managed to hold on to their faith in the face of pagan spirituality, there were others who were deeply compromised. The church shifted from modesty to appeal to the more influential, and prosperous who lived lavish lifestyles. Since Pergamos was known for its wealth, literacy, and pagan philosophy, the church chose to turn away from simple faith and to substitute bible truth with pagan traditions and rituals, undergoing a tectonic shift in thinking to in line with its new congregants.
They were lured into adopting the doctrine of Balaam which was that the men of Israel were seduced by women who invited them to participate in idolatrous and immoral feasts. In John’s letter, Jesus compares this philosophy to the doctrine of Baalam who led the Children of Israel into sin and idolatry through compromise in the wilderness in the book of Numbers.

The Letter to Pergamom
Revelation 2:12-17
“Write to the angel of the church in Pergamum: Thus says the one who has the sharp, double-edged sword: I know where you live—where Satan’s throne is. Yet you are holding on to my name and did not deny your faith in me, even in the days of Antipas, my faithful witness who was put to death among you, where Satan lives. But I have a few things against you. You have some there who hold to the teaching of Balaam, who taught Balak to place a stumbling block in front of the Israelites: to eat meat sacrificed to idols and to commit sexual immorality. In the same way, you also have those who hold to the teaching of the Nicolaitans. So repent! Otherwise, I will come to you quickly and fight against them with the sword of my mouth.
“Let anyone who has ears to hear listen to what the Spirit says to the churches. To the one who conquers, I will give some of the hidden manna. I will also give him a white stone, and on the stone a new name is inscribed that no one knows except the one who receives it.