"Jesus' example teaches us that prayer is about relationship. When he prays, he is not performing a duty; he is getting close to his Father.
Any relationship, if it is going to grow, needs private space, time together without an agenda, where you can get to know each other. This creates an environment where closeness happen, where we can begin to understand each other's hearts.
You don't create intimacy; you make room for it. This is true whether you are talking about your spouse, your friend, or God. You need space to be together. Efficiency, multitasking, and busyness all kill intimacy. In short, you can't get to know God on the fly.
If Jesus has to pull away from people and noise in order to pray, then it makes sense that we need to as well."
- Paul Miller, A Praying Life, page 47