What is a ‘lukewarm’ christian?

Churchgoers are often warned in sermons not to be ‘lukewarm‘ Christians – but what does it really mean?

The message to the church in Laodicea reads as follows: Rev 3:15-16 “I know your deeds, that you are neither cold nor hot; I wish that you were cold or hot. So because you are lukewarm, and neither hot nor cold, I will vomit you out of My mouth.”

Laodicea was known for its trade and just north of them the city of Hierapolis with healthy warm water springs and to the south the city of Colossae with refreshing, cool healing water, was situated. This phrase and the word lukewarm in verse 16 form a metaphor that is based on the quality of the water supply of Laodicea, which was delivered by aqueduct from the hot mineral springs about five miles away. During its journey, the water was dirtied & cooled to a warm or lukewarm temperature and therefor are useless because it is neither cold (refreshing) nor hot (therapeutic).

So what God is saying to them is that their faith became as useless as the lukewarm water they possessed due to their lust after money and power.