They look as if the blessings of God is on them. Though they have a reputation that they are alive and well, the Lord knows their hearts. Though men may not see past all the false fronts placed before them, Christ see them as they are. The Lord see right through us. We are neither cold to those things of God, nor do we have a zeal for them either.
Lets look at what lukewarmness means.
It is a state that you are comfortable in. A comfortable temperature is just right. It is harder for the Lord to use a church or a man who is comfortable than to bring one to repentance and to place the zeal back in the heart. For to be comfortable is to be content in ones knowledge of God. We are commanded to continually grow, not to stagnate.