Laodicea is the center of the imperial cult. It is the wealthiest city in the Phrygean territory. Hierapolis and Colosee are neighboring cities.
Epaphras, possibly one of Paul's Ephesians converts, may have founded these three churches - Colosians 1:7, 4:12,13. This is the last about these churches and so stated in Rev. 4:1 ("After this I looked").
Jesus rebukes the Laodicean church for its lukewarmness in everyday living. The people are self-sufficient and apathetic -- they need to repent and receive true riches and purity and riches from Him. In love, Jesus stand at the door of every heart, knocking to come in. Those who let Him into their lives will enjoy His fellowship.
Lastly, as "victorious believers", they will reign with Him on His throne.