John Piper:

When you take your stand on the finished work of God in Christ, and begin to drink at the River of Life and eat the Bread of Heaven, and know that you have found the end of all your longings, you only get hungrier for God. The more satisfaction you experience from God, while still in this world, the greater your desire for the next. For, as C. S. Lewis said, “Our best havings are wantings.”

The more deeply you walk with Christ, the hungrier you get for Christ . . . the more homesick you get for heaven . . . the more you want “all the fullness of God” . . . the more you want to be done with sin . . . the more you want the Bridegroom to come again . . . the more you want the Church revived and purified with the beauty of Jesus . . . the more you want a great awakening to God’s reality in the cities . . . the more you want to see the light of the gospel of the glory of Christ penetrate the darkness of all the unreached peoples of the world . . . the more you want to see false worldviews yield to the force of Truth . . . the more you want to see pain relieved and tears wiped away and death destroyed . . . the more you long for every wrong to be made right and the justice and grace of God to fill the earth like the waters cover the sea.

If you don’t feel strong desires for the manifestation of the glory of God, it is not because you have drunk deeply and are satisfied. It is because you have nibbled so long at the table of the world. Your soul is stuffed with small things, and there is no room for the great. God did not create you for this. There is an appetite for God. And it can be awakened. . . . (A Hunger for God, 23)

Buy the book A Hunger For God: Desiring God through Fasting and Prayer