As an LCMS "Reformed Catholic", which I somewhat tongue in cheek define as "Catholic with no pope, no worship of Mary or saints, no purgatory, no works righteousness. Yes, that is an oversimplification.
Being "saved" as a too young child praying the "sinner's prayer" that Warren has distilled to "Jesus, I believe in you, and I receive you". Mine was a little longer because I had been traumatized by chalkboard visions of hell at multiple "Special Meetings", and I was in terror of Hell ... so it involved a lot of crying, pleading for Christ to save me me from Hell, admitting that I was a really bad boy, etc, etc. So I definitely feared God!
Then I was Baptized as a "too old" teen, to "follow Christ" with no idea of the saving power of Baptism.
1 Peter 3;20 "to those who were disobedient long ago when God waited patiently in the days of Noah while the ark was being built. In it only a few people, eight in all, were saved through water, 21 and this water symbolizes baptism that now saves you also—not the removal of dirt from the body but the pledge of a clear conscience toward God.[e] It saves you by the resurrection of Jesus Christ"
Thankfully, I was Baptized "in the name of the Father, the Son, and the Holy Spirit". Baptism is God's work, not ours, so even though neither I or the pastor understood the sacramental power of Baptism, I became a child of God.
Being genetically prone to anxiety and depression, I often doubted if I was REALLY sincere when *I* gave my life to Christ. So through multiple "re-dedications", massive guilt over a lot of lusting after beautiful girls in short skirts in the '70s, I "got smart" in college being at best an agnostic, at worst an atheist. Naturally, given my psychological makeup, Hell kept cropping up in the dark of night very frequently, so at least the Holy Spirit was working on me.
LOTS of reading, study, prayer, conversations with various Christian believers in largely Lutheran, Evangelical (often Baptist), Catholic, etc, I arrived at Lutheran ... ELCA, moving to LCMS when celebration of gay "marriage" became an important part of "faith".
While Warren proclaims the book to NOT be a "self help" book, it is. Yes, certainly it is Bible based, and other than the difficult problem of "decision theology" which casts the "God needs you", "worship makes God happy" sort of thinking throughout, the focus is on what you decide/do vs Grace and God's gifts. As with any attempt to create a "process" for Christian life outside of a confessional liturgical church, most everything is "in there", it just doesn't have 2000 years of interaction between Christ and his Bride, the Church.
For anyone reading this that is secular but questioning, I recommend "The Reason For God".
For someone who is struggling to meet some standard of "a Christian life" without the Sacraments, I would suggest "Has American Christianity Failed".
On page 101 Warren tellingly says "you are a spirit that resides in a body". The old Cartesian duality.
Jesus always was and is fully God. In the Incarnation he became fully man as well. When we are Baptized we receive the Holy Spirit. We are flesh and spirit united, which is why we need the physical sacraments, confession/absolution, and holy preaching to grow in Christ. Exactly how our body and spirit are separated at death and reunited at the Resurrection is a mystery, like the "how" of the Trinity. We know through the gift of faith.
John 14:26 "But the Advocate, the Holy Spirit, whom the Father will send in my name,will teach you all things and will remind you of everything I have said to you."
Can sinful man without the Holy Spirit "decide" to "believe"? That is the foundational belief of Anabaptists, of which Rick Warren is one.
Given that many in my family share that belief, as well as many I consider as fellow Christians, I sincerely hope so. One of my many failings is "worship of knowledge". As I have matured I realize there is grave peril there, especially the thought that given what I see as "correct knowledge", I can judge.
I can't! I believe that Christ is merciful, and although he declares the gate is narrow, he does not say HOW narrow. All earthly churches are flawed, and Warren is clear on that truth.
A lot of the book is really about "building numbers" which he clearly has in his Saddleback church, recently thrown out of the Southern Baptist denomination for ordaining women. (I'm with the Baptists on that).
Our world is sorely in need of a "second Reformation" where THE CHURCH can have a third millennium "Council of Nicea". Although America deserves to be treated as Sodom and Gomorrah, or worse, I pray:
Lord, Have Mercy
Christ, Have Mercy
Lord, Have Mercy