Quite simply his argument is: Religion is turning off people of all ages all across America. He has even been turned off by religion in his own personal life. He has concluded that much of religion is "bad," but argues that it doesn't have to be that way. That "good" religion is to be found. People can find places to suit them to worship. They just have to look in the right places.
He spends one third of the book examining "bad religion," a third of the book arguing against "no religion," and a third of the book promoting "good religion." All sections of the book focus in on stories he's sharing with readers to illustrate his points, his worldview.
One can't tell from the basic premise how he defines "bad religion" and "good religion." It is all a matter of perspective. He's writing what he knows, what he believes. It is his book, after all, and "good" and "bad" are certainly prone to subjectivity. Within a few pages, I got a good idea of where he was heading. I was disappointed, but, not surprised, not really.
I don't want to rush in and say that everything in the book is theologically wrong, or, that he is never, ever, ever right. Sometimes his conclusions contain (some) truth at least, but his reasoning--his system of working it out--is faulty. Sometimes his observations were true (mostly true) but he somehow came to the wrong conclusions.
For example, you could say he has strong, negative feelings for anyone who holds the Bible to be infallible or inerrant. He claims this is not the historic Christian position. (That this is an invention of the twentieth century.) If you hold the Bible to be a divine book, a book that is God-breathed, a book that is all true and not just mostly true or sometimes true, then he is quick to judge you.
The root of most "bad religion" in his opinion is people who take the Bible too seriously. His examples are not just pushing the extreme, but pushed to the very extreme. "Christians" who hold this view are loud, arrogant, rude, in-your-face, wear offensive t-shirts, carry offensive signs, joke about killing people who disagree with them, laugh about people burning in hell for eternity. In other words, people defined by hate, hate, bitterness, anger, and did I mention, hate. What I found disturbing is that he presents this--it seems he presents this--as the normality. "All Christians who hold the Bible to be infallible and God-breathed" are like this.
It must be impossible, according to him, to hold that a) all people should be treated with kindness, respect, dignity regardless of what they may or may not believe, or what they may or may not think about any given issue (for example politics, abortion, immigration, essentially any "hot" or "current" topic, etc.) AND b) hold the Bible to be true, to be infallible, the very Word of God. His assertion that it is only those that free themselves from the "literalness" of the Bible that are free to live lives of love and keep the peace with their neighbors is disturbing.
The only Christians who are loving, compassionate, given to service, joyful, thankful, humble, fun-to-be-around ARE those who have rejected certain claims about the Bible, and have a better "informed" faith that is more open-minded, inclusive, and tolerant. Those willing to embrace ambiguity and mystery and reject certainty. (Now for the record, there are hundreds--if not thousands--of mysteries that we will never know this side of eternity. And I am not claiming that anyone can fully, absolutely, completely grasp or understand the heart-and-mind of God as He really is. But, for example, to deny there are certainties in the Bible is pushing it too far. God has revealed who He is. He has given us a book--the Bible--and given us His Spirit, the Holy Spirit. So we can know some things without doubt.) Also the author believes that the Bible is full of contradictions, contradictions that cannot be explained or reconciled.
Now, to clarify, he is not denying that the Bible is important, or denying that the Bible is a significant, potentially life-changing book. He affirms its inspired-ness. But I got the sense, I could be wrong, that the way he uses the word "inspired" does not mean God-breathed, God-authored. But instead means, "I was inspired to write this poem by my walk in the woods." "I was inspired to write this song for the most beautiful woman in the world, my wife." In other words, perhaps more like how a movie is "inspired" by "true events."
For example, I believe his argument was that the human authors were trying their best--to the best of their limited ability--to write true things of God, to write what they understood at that time, in that place, to be true of the God they worshiped. But not being God, they sometimes got things wrong. Of course, they sometimes got things right. It was up to future generations to "correct" misconceptions and "fix" the faith so that it better reflected what they themselves thought was true about God. And so it is to this day. "The God I worship would not…."
His way of understanding or comprehending what is meant by a "literal view of the Bible" is a bit frightening. I don't think he did his opponents justice in representing what they actually believe. Or perhaps there are a dozen ways one could theoretically take the Bible literally--and he assumes that the weakest, most ridiculous one is the only one. There are probably hundreds of books on how to read the Bible that would clarify the subject. He misunderstands quite a few things that are basic to reading and interpreting the Bible.
Some core (essential) doctrines he appears to sincerely, legitimately believe and hold closely and respectfully. For example, the resurrection of Jesus Christ, and the hope of our future resurrection. I say appear not to be sarcastic--I'm not trying to be--but because he probably clarifies and explains his beliefs a lot better in a previous book that I've not read.
If there is a section of this one that comes closest to the truth--something I view as absolute, and something he would view as relative, I'm sure--it is his section on "good religion." He makes a few good points now and then. One chapter that I agreed with most of the time was on the dangers of nominal commitment to Christ and the church.