Note to reader: I have not read anything by Rick Warren, even though I am about to comment on his work. I have gained knowledge of his ideas via third parties that in fact have read his work. I consider this just as valid (at least for my purposes here of general critique) as watching the news about China and then speaking about it, even though I haven't actually been to China either.
Rick Warren has successfully summarized the whole of Western Christianity, and that is why his books have been so wildly successful. (His book sales rival Stephen King's in the 1980's). He places man at the center of his own destiny, which most church-goers have been taught since the Scopes Monkey Trial. For Warren, man's plight is his own subjugation, by his own will. Worship God, disciple others for Christ, and the traditional litany (here, litany = empty ritual) of human responses to God's gift of eternal life.
Warren, and the modern church by extension, work primary in direct opposition to God's explicitly defined plan for our lives. The purpose driven life for Warren is one of duty and action which brings honor to God. This is right out of the Crusades, and it can probably be assumed that President Bush was delighted with the PDL ideas as he has moved to conquer Babylon (modern day Iraq).
In Romans, Galatians, Hebrews, and Titus, Paul explains that God's work indeed took the place of our work. Christ on the cross ended his human life with "It is finished". Christ ended his and our work. He ended our reliance on formulas (like OT law and Rick Warren's writings) in order to be worthy before God. Christ sits at the right hand of the Father. We are to emulate Christ now, not necessarily Christ's action when he was here on earth. We are to sit. The Holy Spirit is the actor in our lives now.
We can elect to start running around and doing things for God, but God has told us to simply stand, abide, rest, and end our own work. A friend described it this way: we are probably doing God's work when we do that which we would otherwise simply not have thought to do on our own. There is no formula for letting God though the Holy Spirit work though us. It will look differently for everyone. The experience will largely be ethereal and difficult to describe later. Most of God's work will not submit to the 5 convenient categories Rick Warren puts forward. It will, however, be easy to say to others that God did this or God did that. We know what we are capable of, and when we go beyond that , it is God.
Warren want us get control of our lives, but God actually wants that job.