In the house of the Lord there is no place for Lukewarm and Cold Christians (Revelation 3:15). Jesus want to see His people on fire. Because the Lord of new testament is also consuming Fire (Hebrew 12:29). But today fire of God is removing from people because of less Prayer. 

     We are living sacrifice to God (Romans 12:1), but people put less Praise, less Worship, Less Prayer on the Altar. As a result no fire fall to accept their offerings. So Jesus warn to keep you warm - Watch and Pray.