How is it that many true believers often pray so coldly? What is the reason that their prayers are so feeble, wandering and lukewarm, as they frequently are? The answer is very plain:
their sense of need is not so deep as it ought to be. They are not truly alive to their own weakness and helplessness, and so they do not cry fervently for mercy and grace. Let us remember these things. Let us seek to have a constant and abiding sense of our real necessities. If saints could only see their souls as the ten afflicted lepers saw their bodies, they would pray far better than they do.
~ J.C. Ryle
Expository Thoughts on the Gospels: Luke volume 2 , [Carlisle, PA: Banner of Truth, 1986], 232. {Luke 17:11-19}