[Early morning prayer] signals to our conscience that this is of first importance in the day. That witness from our action to our conscience has a joyful effect on the Christian mind. Second, early morning prayer strikes the first blow in the battle of the day, instead of waiting till we are besieged from all sides. Third, what we do daily and do early shapes the spirit of our minds and brings us into a disposition of humility and trust that will bear better fruit than anxiety or self-reliance. Fourth, since beginning the day with the Word of God is crucial, therefore prayer is equally crucial since the Word will not open its best wonders to us without prayer: "Open my eyes, that I may behold wondrous things out of your law" (Ps. 118:18). Fifth, it is uncanny how Satan can use even good things to squeeze prayer out of our schedule if we miss the early-morning hour. I have seen it again and again. If I say to myself, "I will give some time to prayer later," it generally does not happen.

John Piper, When I Don't Desire God: How to Fight for Joy, p. 159