I have found for thirty years that preaching and teaching about God's demand that we delight in him more than anything else breaks and humbles people, and makes them desperate for true conversion and true Christianity. Oh, how easy it is to think we are what we ought to be when the emotions are made peripheral. Mere thoughts and mere deeds are manageable by the carnal religious mind. But the emotions--they are the weathercock of the heart. Nothing shows the direction of the deep winds of the soul like the demand for radical, sin-destroying, Christ-exalting joy in God.

John Piper, When I Don't Desire God: How to Fight for Joy, p. 31

It is as plain to me as anything, that the first thing the child of God has to do morning by morning is to obtain food for his inner man.

As the outward man is not fit for work for any length of time, except we take food, and as this is one of the first things we do in the morning, so it should be with the inner man. We should take food for that, as every one must allow. Now what is the food for the inner man: not prayer, but the Word of God. . . . How different when the soul is refreshed and made happy early in the morning, from what is when, without spiritual preparation, the service, the trials and the temptations of the day come upon one!

George Mueller, Autobiography of George Mueller

There exists a delight that is not given to the wicked, but to those honoring Thee, O God, without desiring recompense, the joy of whom Thou art Thyself! And this is the blessed life, to rejoice towards Thee, about Thee, for Thy sake.

Augustine, Confessions