[See Seven Churches]
Laodicea was a city in Asia Minor, a hub of transportation, which led to the development of commerce and made it a very wealthy city. Also, an eye medicine called 'Phrygian,' which was said to cure eye diseases when applied to the eyes, was famous here.
Therefore, in the Book of Revelation, when criticizing the church here, "gold" and "eye medicine" are mentioned.
Rev 3:18I counsel you to buy from me gold refined by fire, that you may be rich; and white garments to clothe yourself, that the shame of your nakedness may not be seen; and salve to anoint your eyes, that you may see.
The city of Laodicea was famous from ancient times for its developed medicine and for producing many ingredients for eye medicine.
This church is the only one among the other seven churches mentioned in Revelation that received no praise.
Paul mentioned the church in Laodicea in Colossians, telling them to exchange and read the letters sent to both sides.
Col 2:1For I want you to know how great a struggle I have for you and for those at Laodicea and for all who have not seen me face to face,
Col 4:12Epaphras, who is one of you, a servant of Christ Jesus, greets you, always struggling on your behalf in his prayers, that you may stand mature and fully assured in all the will of God.Col 4:13For I bear him witness that he has worked hard for you and for those in Laodicea and in Hierapolis.Col 4:14Luke the beloved physician greets you, as does Demas.Col 4:15Give my greetings to the brothers at Laodicea, and to Nympha and the church in her house.Col 4:16And when this letter has been read among you, have it also read in the church of the Laodiceans; and see that you also read the letter from Laodicea.