Open the front cover of this book, and you'll see a four-color glossy reproduction of Rembrandt's "The Return of the Prodigal Son," which captured the imagination of the late Henri Nouwen, whose best book personalizes that painting's characters and themes.

Inspired by Nouwen, McMinn, a psychology professor at Wheaton College (Illinois), went to St. Petersburg, Russia to "sit with" the Rembrandt and there decided to write this book about sin and grace --- far different, he says, from a never-published "book about grace" he wrote 15 years ago. The difference? From the perspective of empty-nest, middle age, he sees that one cannot understand grace "without understanding sin."

After two introductory chapters grounded in his epiphanic reaction to the Prodigal Son parable and painting, McMinn looks at sin from three perspectives: theology, psychology and spirituality. Noting the problems with a prevalent, secular "I'm OK, you're OK" mindset and a judgmental "I'm OK, you're a mess" stance, he concludes that it's wiser and more realistic, albeit countercultural, to admit, "I'm a mess, you're a mess." The voice of this humble stance draws the reader in; it turns what could have been an analytical book into an insightful, refreshing read. Through revealing (but not too) personal anecdotes, McMinn, the professor and expert, becomes a fellow traveler. "Our greatest hope is going through a long, slow process of understanding our messes, acknowledging our part in the problem, then seeking resolution and restoration."

Being a psychologist, not a theologian, his insights get better as the book progresses, but early on he does lay out good distinctions among three dimensions of sin: sinfulness, the "white noise" of original sin that "touches every aspect of our existence"; sins, the choices we make to "violate God's instruction"; and the consequences of sin, our own and others'. The point of this synopsis? "Only as we begin to grasp the immensity of the sin problem are we able to glimpse the depth of God's grace, and paradoxically, seeing God's grace gives us courage to face our sinfulness."

Much of part 2, "The Damage Report," which discusses the psychological perspective of sin, hones in on pride, "the utmost evil," according to C. S. Lewis --- how it wreaks havoc in our passions ("in our pride we love and hate the wrong things," writes McMinn) and also in our minds ("pride taints our thinking as well as our affections"). McMinn then spends a chapter acknowledging that we are not sinful trash but rather "noble ruins" --- made in the image of God.

Part 3, "Homeward Bound," draws us toward God and the grace he offers --- through himself and through people working on his behalf --- notably as we admit our sinfulness and sins. The best lines in the book may be those under the heading "Repentance and Forgiveness": "Time does not heal all wounds. Time heals clean wounds. Soiled wounds fester and infect, leading to bitterness and cynicism, to terrorism and war, to divided marriages and wounded children ...

"When we humbly admit our weaknesses and faults to God and to one another, we create the possibility for the intimacy we long for and we catch a glimpse of heaven."

It's hard to categorize this book. It is not self-help or how-to. Nor is it heavy theology (for all the talk of sin and grace, there isn't much technical talk of the Atonement). Nor is it a devotional. This is not a book for or of interest to men more than women. (Having said that, I note that in seven pages of endnotes, McMinn cites only two women; surely this says something about our fallen world, though it's hard for me to articulate what.)

Like the works of Henri Nouwen, WHY SIN MATTERS is a thoughtful, insightful nudge toward spiritual and psychological growth. It could well complement pastoral or clinical therapy. Its insights will be valuable for anyone who has sung John Newton's "Amazing Grace" and resonated with or has conversely been repulsed by its most difficult phrase: "a wretch like me."