Revelation 3:14-16 (KJV)
14 And unto the angel of the church of the Laodiceans write; These things saith the Amen, the faithful and true witness, the beginning of the creation of God;
15 I know thy works, that thou art neither cold nor hot: I would thou wert cold or hot.
16 So then because thou art lukewarm, and neither cold nor hot, I will spue thee out of my mouth.
The overall spiritual temperature of the church is based on the temperature of what comes from behind the pulpit.