Many who read these verses conclude that hot, cold, and lukewarm are three distinct categories of a person's moral or spiritual condition. Traditionally, "hot" is understood to refer to Christians on fire for the Lord, "cold" refers to non-Christians totally opposed to the Lord, and "lukewarm" refers to Christians who appear to be unable to let go of the world but still want to be religious. But, is this really what Jesus meant? Did our Lord imply that He would prefer one to be involved in the ungodliness of paganism instead of being a partially committed Christian? I believe the answer to both questions is "no," and an analysis of the historical situation of Laodicea is quite valuable in understanding these verses.
I have read about an archaeological visit that J.S. Rudwick and E.M.B. Green made to Laodicea over fifty years ago. They recorded some intriguing facts about the city. First, Laodicea did not have a local water supply. Rudwick and Green discovered an aqueduct in the southern part of the site which indicated Laodicea received its water from the modern town of Denizli, five miles south. Since hot mineral springs are common in that area, and the aqueduct was coated with mineral deposits, Rudwick and Green concluded that Laodicea's source of water must have been one of the hot mineral springs. Therefore, in order for Laodicea to receive its water, the water traveled through the aqueduct some five miles. While in the aqueduct the hot mineral water slowly cooled and was lukewarm when it arrived in Laodicea. All people in the area of Laodicea knew that lukewarm mineral water would disappoint the thirsty traveler. It would only make a person want to spit the water out. Consequently, after the lukewarm water arrived in Laodicea the people had to allow it to cool before drinking it.
Further, it is valuable to know something about the water of two of Laodicea's closest neighbors. Hierapolis, located a few miles north of Laodicea, had hot spring water which was recognized to have some medicinal value. The Greek word zestos (hot) would likely remind the Laodiceans of their neighbor's water. Also, the city of Colossae was only a few miles away. Psuchros (cold) describes Colossae's water, a very precious element in that area. Cold water is always useful and especially so in the first century. The weary, thirsty traveler would find refreshment from the cold water of Colossae.
In view of this information concerning the water of Laodicea, Hierapolis, and Colossae, it seems appropriate to reconsider "hot," "cold," and "lukewarm" in Revelation 3:15,16. The hot water of Hierapolis was useful in that it helped the sick become well again. The cold water of Colossae provided refreshment for the weary. Laodicea's lukewarm water, however, was worthless. Is it possible the Laodiceans' Christianity is being compared to their lukewarm, sickening water? If so, "hot," "cold," and "lukewarm" are not so much degrees on a "spiritual thermometer" as they are illustrations from the historical context. Hot and cold water were useful, and if the Laodicean Christians had been either "hot" or "cold" they also would have been useful to the Lord. Unfortunately, the Laodiceans were lukewarm. Just as their water made one sick, so their form of Christianity made God sick. "Hot" and "cold" are commendable characteristics, but lukewarm Christianity upsets the Lord's stomach, so to speak. The text itself implies that the Lord would not spit out those who were "cold" or "hot"--only those who were "lukewarm." This strongly suggests that God would be pleased with one being either "cold" or "hot." Therefore, being "cold" cannot refer to atheism or paganism, since certainly the Lord would not be pleased with such.
What was the sin of the Laodicean church? Why were they compared to their own water? According to Revelation 3:17,18, they had been blinded by materialism. Although they were materially rich and doing well physically, they were spiritually poor, not even realizing their wretched state. No one is immune from this same problem today. Friends, seek to be useful in the Lord's kingdom according to your abilities. Be a good steward and fully dedicate yourself to serving God. The Lord will spit out the lukewarm!