Laodicea was a city in Asia Minor in the first century. It was one of seven cities mentioned in the prophecy of Revelation 2 and 3; there was a congregation of the Church of God in each city. Jesus used unique characteristics about not only the congregations, but also about the cities in which they were located, to teach Christians important lessons.
Laodicea was well known in the ancient world for its wealth. "For example, in 62 B.C. Flaccus seized the annual contribution of the Jews of Laodicea for Jerusalem amounting to 20 pounds of gold" (Nelson's Illustrated Bible Dictionary, 1986, "Laodicea").
"The extent of its wealth is illustrated by the fact that Laodicea was rebuilt without the financial help of Rome after the disastrous earthquake of A.D. 60. Laodicea earned its wealth in the textile industry in the production of black wool and in the banking industry. Laodicea was also known for its medical school [school of ophthalmology] which concocted a spice nard for the treatment of the ears and an eyesalve. The major weakness of Laodicea was its lack of a water supply. This need was met by bringing water six miles north from Denizli through a system of stone pipes [water conveyed to Laodicea through these pipes was lukewarm by the time it reached the city]" (Holman Bible Dictionary, 1994, "Laodicea").
The eye salve was called "collyrium," probably a reference to how it was applied—that is, in the form of plaster or a poultice.
Christ, always the quintessential teacher, integrated these well-known facts about Laodicea into His spiritual message about them. He warned against a lukewarm, self-sufficient and self-satisfied attitude:
"I know your works, that you are neither cold nor hot. I could wish you were cold or hot. So then, because you are lukewarm, and neither cold nor hot, I will vomit you out of My mouth. Because you say, 'I am rich, have become wealthy, and have need of nothing'—and do not know that you are wretched, miserable, poor, blind, and naked—I counsel you to buy from Me gold refined in the fire, that you may be rich; and white garments, that you may be clothed, that the shame of your nakedness may not be revealed; and anoint your eyes with eye salve, that you may see. As many as I love, I rebuke and chasten. Therefore be zealous and repent" (Revelation 3:15-19).
Then Jesus said the same thing about the spiritual lessons He drew from Laodicea that He said about each of the seven churches: "He who has an ear, let him hear what the Spirit says to the churches" (Revelation 3:22).
It is entirely possible that Jesus also intended to embed a chronological prophecy of successive eras, each characterized by the predominant strengths and weaknesses of the seven churches and the cities in which they were located. In recent years, some Christians seem to focus more on that possibility than on what we can know with certainty—that we need to apply all of the messages to all of the churches to ourselves. Is there anything helpful or godly in one person or group pointing a finger of judgment, declaring another person or group to be "Laodiceans"? But, on the other hand, it is wise for each of us to be on guard against the Laodicean weaknesses in ourselves.