Sardis was a famous ancient city, originally the capital of the Lydian Kingdom. It was situated on the banks of the Pactolus River, which was legendary for its gold-bearing sand. With five major roads converging there, it was a prosperous commercial hub, where wealth came easily, and its rulers and citizens grew complacent and lazy. The city was divided into an upper and a lower city. The acropolis, built on a steep, rugged mountain, was easy to defend and difficult to attack. Yet, due to a lack of vigilance, its defenders neglected cracks in the cliffs. The city was twice captured by surprise attacks, once by King Cyrus of the Persian Empire and another time by the army of Antiochus III of the Seleucid Empire. A massive earthquake hit the city in 17 AD, but with economic aid from Emperor Tiberius, it was quickly rebuilt.
Although the church in Sardis was in the best situation of all the churches—facing none of the pressure, persecution, or temptation that the others did—it only had the appearance of “deeds.” In reality, these deeds were not expressions of genuine spiritual life. It looked as though it were alive and well, but it was, in fact, a name without reality, on the verge of death. This church had no zeal for false doctrines, nor did it have any interest in contending for the truth. It was indistinguishable from the secular world, so false prophets, Jews, and Romans didn’t bother to touch them, and their lives were without pressure.
In the church of Ephesus, heresy was “hated.” In the church of Pergamum, some people had already “held” to the teaching of false doctrine. The church of Thyatira even “tolerated” a false prophetess who taught its members. But in the church of Sardis, only “a few names” were left who had not “soiled their clothes.” Believers are saved sinners, but Adam’s sinful nature is not eradicated. Therefore, if the church does not remain holy and hold fast to the truth, any tiny crack in the dam of truth will lead to a complete moral collapse.