There were many things I enjoyed about Paul Miller's A Praying Life; one of those things was the connection that Miller made between prayer and the Gospel. Here's one of my favorite quotes:
Prayer mirrors the gospel. In the gospel, the Father takes us as we are because of Jesus and gives us his gift of salvation. In prayer, the Father receives us as we are because of Jesus and gives us his gift of help. We look at the inadequacy of our praying and give up, thinking that something is wrong with us. God looks at the adequacy of his Son and delights in our sloppy, meandering prayers.
If, like me, you desire a more enthusiastic, disciplined and joyful prayer life, Miller's book is an excellent read.