Piper on Authentic Worship

"Let me mention here that this does not mean that worship is authentic only when you are red-hot for God. It can mean that when you are not red-hot, your heart feels a longing for the passion that you once knew or want to know more of. That longing, offered to God, is also worship. Or it can mean remorse that even the longing is gone, and you are scarcely able to feel anything but sadness that you don't feel what you should. That remorse, offered to God, is also worship. It says to God that he is the only hope for what you need. So don't have an all-or-nothing attitude about worship. The heart can be real even if it is not as enflamed with zeal as it ought to be - which it never is in this life."

John Piper – Singing and Making Melody to the Lord