One of the earliest mentions of “the church” in the New Testament comes from the lips of Christ in Matthew 18. There, His first message to the church is for dealing with sin in the assembly. Like His parting words to the churches in Revelation 2–3, Christ’s instructions to His church are wholly concerned with the holiness and spiritual health of the church herself. He did not issue a manifesto instructing His people to engage or redeem secular culture. He didn’t present a strategy for assessing and addressing the felt needs of the community, or ending cultural inequity, or lowering the poverty rate. He didn’t lay out a plan for maximizing the church’s political or moral clout. He didn’t stress the need for tolerance, validation, spiritual safe spaces, or any of the other currently fashionable evangelical talking points. Instead, His concern was for the purity of His church. He wanted His people to know how to confront and deal with sin.

If your brother sins, go and show him his fault in private; if he listens to you, you have won your brother. But if he does not listen to you, take one or two more with you, so that by the mouth of two or three witnesses every fact may be confirmed. If he refuses to listen to them, tell it to the church; and if he refuses to listen even to the church, let him be to you as a Gentile and a tax collector. (Matthew 18:15–17)

This unambiguous command for confronting sin in the church is an entirely counterintuitive idea for the hip, cool, modern church. Many think, Who am I to tell someone else how to live? Why would we want to expose people’s sin or force anyone out of the church? Shouldn’t we just love them and let the Spirit do His work?

Incredibly, many churches today proudly ignore the sin in their midst in the name of tolerance, unity, and love—proving only that they have no true understanding of what the Bible means when it talks about unity and love. Amazingly, ignoring sin and practicing tolerance has become a staple strategy for church growth. This directly defies the Lord’s commands.

The apostle Paul harshly rebuked the Corinthians for that very attitude in 1 Corinthians 5. A man in their midst was openly indulging in an incestuous sin so egregious that even Gentiles in the community were shocked by it. “Someone has his father’s wife” (1 Corinthians 5:1). Instead of excommunicating the man, they boasted about their tolerance, as if it were a badge of honor to allow such a person to represent their fellowship in the community. Paul told them, “You have become arrogant and have not mourned instead, so that the one who had done this deed would be removed from your midst. Your boasting is not good. Do you not know that a little leaven leavens the whole lump of dough?” (1 Corinthians 5:2, 6). Not only was the testimony of the entire church ruined by the open sin of this man; sin itself increases in the church like leaven. Such wickedness, when tolerated, will spread and poison the whole fellowship. The effects of that principle were already clearly evident in the Corinthian assembly.

The apostle’s instructions were straightforward and urgent: He commanded them “not to associate with any so-called brother if he is an immoral person, or covetous, or an idolater, or a reviler, or a drunkard, or a swindler—not even to eat with such a one. . . .  Remove the wicked man from among yourselves” (1 Corinthians 5:11, 13).

Though sin spreads like leaven, purity and holiness do not. They must be diligently cultivated and protected. Many in the church today seem to be laboring under the bizarre notion that an “acceptable” amount of sin in the church is an evangelistic strategy. They pretend that the Lord’s view of unrighteousness and corruption is as casual as theirs is. Believers must defend the purity of the church above all other concerns, regardless of how doing so might offend observing sinners.

In Ephesians 5:25–27, Paul describes the Lord’s love for His church and His abiding concern for her purity. He says Christ “loved the church and gave Himself up for her, so that He might sanctify her, having cleansed her by the washing of water with the word, that He might present to Himself the church in all her glory, having no spot or wrinkle or any such thing; but that she would be holy and blameless.” Our priorities for the church need to reflect the Lord’s. We need to prize the purity of the church as He does.

Consider the ways that overlooked and ignored sin inhibits the work of God’s people. He has called the church to be heaven’s representative on earth. The church is the place where God is to be honored and glorified, where righteousness is exalted and holiness pursued. In fact, God’s people are called to reflect His holiness as a testimony to the unrepentant world (Matthew 5:16). We can’t do that if we’re tolerating sin in our midst.

Despite Scripture’s clear instructions, many churches that declare sound doctrine fail to declare and protect holiness. Christ’s letter to the church at Thyatira illustrates the deadly consequences of failing to guard the purity of God’s church.

Built for Destruction

Thyatira, the smallest of the cities mentioned in Revelation 2–3, was located approximately forty miles to the southeast of Pergamum, along the main road traveling north and south. Though it sat in a flat river valley that lacked any natural fortifications, it was originally founded as a military garrison on the main road to Pergamum. The plan was that any attackers headed toward Pergamum would be slowed by the soldiers at Thyatira, buying precious time for Pergamum to prepare its own defense. As the capital city of the region, Pergamum would surely be the destination for invading forces; Thyatira was merely a speed bump along the way. Therefore, Thyatira was frequently destroyed and rebuilt throughout its history. In the few instances the city is referenced in ancient literature, it is usually to relay the details of its conquest.

Things changed for Thyatira after it came under Roman control. The relative peace brought by the Roman Empire spared the city from constant attack and destruction. And its location along a major trade route connecting Pergamum with Laodicea and Smyrna turned Thyatira into a boomtown for commercial industry. The city specialized in dyed fabrics—particularly a purple dye developed from a combination of shellfish and root—but it was home to all sorts of ancient tradecrafts. History suggests the city was still ascending in prominence when John saw his vision of Christ on Patmos. Today, it is the Turkish city of Akhisar.

Scripture doesn’t tell us when the church at Thyatira was founded. It could have been during Paul’s ministry in Ephesus (Acts 19:10). It also could have blossomed out of his earlier ministry in Philippi. In the book of Acts, Luke tells us, “A woman named Lydia, from the city of Thyatira, a seller of purple fabrics, a worshiper of God, was listening; and the Lord opened her heart to respond to the things spoken by Paul” (Acts 16:14). Lydia and her family were the first believers in Europe and helped establish the Philippian church. It’s possible that she or some of her relatives returned to Thyatira and helped establish a gospel outpost there.

No matter how the church in Thyatira began, it’s instantly apparent from Christ’s letter that they had not remained faithful to the truth, or to His instructions to keep the church pure. In fact, the congregation was inviting God’s wrath and judgment through their corrupt behavior.

A Word from the Judge

The Lord’s letter to Thyatira marks a shift in the language and tone of His correspondence. In the first group—the letters to Ephesus, Smyrna, and Pergamum—the churches had stayed true to the faith and had not yielded to the assaults of sin. Ephesus was characterized by loyalty to Christ and sound teaching, but was lacking love. Smyrna’s loyalty to the Lord had been tested by fire, and they had faithfully persevered. Even to the compromising church of Pergamum, the Lord praises some of them for holding fast to His name.

Not so for the church in Thyatira, or for those to follow in Sardis and Laodicea. In these cities, the situations were far worse. It was no longer a small minority of the believers who were sinning. These churches were dominated by the satanic influences of false teaching and immorality, and the letters to them indicate the Lord’s wrath over their impurity.

That’s reflected right from the start in the letter to Thyatira, as the Lord identifies Himself as “the Son of God, who has eyes like a flame of fire, and His feet are like burnished bronze” (Revelation 2:18). In each letter, Christ borrows imagery from John’s initial vision that ties to the nature of His message to the church. To Ephesus, He emphasized His authority and care for the church (Revelation 2:1). For Smyrna, He reminded them of His eternal nature, His sacrifice on their behalf, and the glories that awaited them in heaven (v. 8). And in bringing a firm rebuke to Pergamum, He identified the power of His Word and the consequences to come if they failed to repent (v. 12).

His self-description to Thyatira similarly foreshadows His message to the church. Here He is characterized by His “eyes like a flame of fire,” which signify His perfect omniscience. There was nothing going on in the church at Thyatira that He did not know about, no secret sin that had escaped His notice (see Matthew 10:26). It was a reminder that “there is no creature hidden from His sight,” but that “all things are open and laid bare to the eyes of Him with whom we have to do” (Hebrews 4:13). Nothing can be hidden from the eyes of the Lord.

Along with His penetrating, laser-like gaze, Christ describes His feet “like burnished bronze”—a depiction of His authority and judgment over His church. That imagery will come up again later in Revelation, when John describes the Lord’s wrath poured out against the unrepentant world. He writes that Christ “treads the wine press of the fierce wrath of God, the Almighty” (Revelation 19:15). Here, the Lord’s feet glow “like burnished bronze” as He tramples the impurity festering within His church.

There is one notable difference from the wording of John’s original vision. John writes that he “saw one like a son of man” (1:13), emphasizing not only Christ’s humanity but also His compassion and care for His people. It reflects His intercessory work on our behalf and His understanding of our weaknesses, failures, and struggles. In Revelation 2:18, Christ instead refers to Himself as “the Son of God.” This is an affirmation of His deity and, with it, His transcendence, holiness, and judgment. The Savior has become the Judge; the Intercessor becomes the executioner. Divine wrath is about to be unleashed against this idolatrous, immoral congregation. This is not comforting or sympathetic; this is threatening and fearful. This is a letter no church wants to receive.

(Adapted from Christ’s Call to Reform the Church.)