The church today, the church “of Jesus Christ,” is working very hard to be as much like the culture as possible, instead of fleeing those things.

For decades, it has been popular for church leaders to make people come to church and feel like they’re at some worldly event. Church has become sinner-friendly instead of sinner-frightening. It’s become affirming rather than convicting, sentimental rather than theological, informal rather than solemn, entertaining rather than edifying, deceptive rather than honest, frivolous rather than worshipful — you get the idea.

Churches don’t like the idea that they’re an offense to the culture, and they think that if they can just get close to everything that people enjoy in the culture, they can somehow win them over.

How did we get here? There are philosophical currents that have pushed us in this direction, like pragmatism. Pragmatism is a philosophy that says the worth of anything is determined by its practical consequences. That’s a little different from another philosophical trend, utilitarianism. Utilitarianism says usefulness is the standard of what is good. If it works, if it produces the desired effect, then we do it. This is the philosophy.

The church, strangely enough, has bought into the philosophy of pragmatism and utilitarianism and decided that if it draws a crowd, it’s good; and if it works, we’re going to use it, even if it fails to be a separation from the world.

So the church has adapted to the pagan world. Leaders in the church talk less about theology and more about methodology. They talk less about doctrine and more about strategy.

As the pagan world becomes more hostile to the truth of God, as it becomes more hostile to the people of God, churches will compromise. They’ve already shown they will do that. They will compromise to be more attractive. They don’t want to be persecuted, they don’t want to be rejected, they don’t want to be ignored, they don’t want to be persecuted, and so they’ll fall in line with the expectations of the world. They’ll court the world by being like the world.

Jesus says this to the church in Pergamum:

I have a few things against you, that you have there some who hold the teaching of Balaam, who kept teaching Balak to put a stumbling block before the sons of Israel, to eat things sacrificed to idols and to commit sexual immorality. So you also have some who in the same way hold the teaching of the Nicolaitans. (Revelation 2:12-15)

You have some people there who are messing around with idolatry and immorality. It’s sort of like Balaam, and it’s what the Nicolaitans advocate. You’ve got people being sucked back into the very familiar sins from which they’ve been delivered.

Balaam, according to Deuteronomy 23, is an Old Testament character. He was a renowned sorcerer from a place called Pethor in Mesopotamia. He was aware of the God of Israel — everybody was aware of the God of Israel because of what the God of Israel had done in delivering His people from Egypt. But Balaam was a sorcerer who was in it, like all sorcerers, for the money. And so he made his rather esoteric services available to anyone who paid him.

You remember the story. Three times Balaam tries to curse Israel, but he can’t do it. So he develops another strategy. If he can’t curse them, he decides he will corrupt them. So he got a bunch of Moab’s women to seduce Jewish men into intermarriage; and thus he pulled those men into idolatrous, immoral life in Moab. They went back into eating things sacrificed to idols, and back into committing idolatry — the very things they had seen in Egypt.

The curse didn’t work, but the corruption did. Blasphemous union with the world destroyed Israel’s power and removed their protection. The plan was successful. But God, in Numbers 24, intervened, severely chastening Israel and the leaders and halting their slide.

So the point that our Lord is making to the church in Pergamum is, “You have some people there who are acting like Balaam, and they’re seducing you to go back into the very culture you’ve been delivered from, to participate in their idolatry and their immorality.” Some in Pergamum were falling to the seducing sirens of the devil’s culture.

Practically speaking, what did it look like? Some in the Pergamum church were attending pagan feasts with debauchery and immorality, and then they were coming to church. And apparently the church had not taken action to confront and correct it.

And what about the Nicolaitans? What was their issue? It was essentially the same as those following the error of Balaam. It was drawing people back into the world from which they’d been rescued.

Two of the early church fathers, Irenaeus and Clement of Alexandria, wrote this about the Nicolaitans: “They live lives of unrestrained indulgence, abandoning themselves to pleasure like goats, leading a life of self-indulgence.”

The church at Pergamum had people living like pagans, and the church had tolerated this teaching and this compromise, corrupting the household of the Lord. They weren’t separated.

So Jesus commands, “Repent.” Turn and go the other way. Stop tolerating worldly compromise.

If you have people in your assembly who are coming to worship Christ and then going right back out and falling into the sins of the culture, you must confront them. The church today must not fail to exclude unbelievers from the fellowship of the body of Christ. We’re always glad when unbelievers come and hear the message, but you can’t participate with the people of God until you are a child of God.

The church must confront professing believers who are living sinful lives, who claim to have been delivered and redeemed out of the world but are literally living the way the world lives. They have to be confronted.

If we don’t do that, look at the “or else”: “But if not, I am coming to you quickly, and I will make war against them with the sword of My mouth.” This is a church on the brink of judgment.

Now, of course, we want to reach out. We want to welcome unbelievers to hear the gospel and be redeemed. We want sinning believers to be given grace and abundant forgiveness. But we don’t tolerate sin as if it’s acceptable, and we don’t live as close to the corruption of the world as we possibly can.

This post is based on a sermon Dr. MacArthur preached in 2015, titled “The Lord’s Word to His Church: Pergamum.” In addition to serving as the pastor of Grace Community Church and the voice of Grace to You, Dr. MacArthur is the chancellor of The Master’s University in Santa Clarita, Calif. You can learn more about TMU at masters.edu.