Raised in a secular family but increasingly interested in the relevance of faith in our modern world, A.J. Jacobs decides to dive in headfirst and attempt to obey the Bible as literally as possible for one full year. He vows to follow the Ten Commandments. To be fruitful and multiply. To love his neighbor. But also, to obey the hundreds of less-publicized rules: to avoid wearing clothes made of mixed fibers. To grow his beard. To stone adulterers.

The resulting spiritual journey is at once funny and profound, reverent and irreverent, personal and universal. Jacobs also embeds himself in a cross-section of communities that take the Bible literally, including the Amish and the Hasidim. He discovers ancient Biblical wisdom of startling relevance. And he wrestles with seemingly archaic rules that baffle the 21st-century brain.

Jacobs's extraordinary undertaking yields unexpected epiphanies and challenges. Sure to charm listeners both secular and religious, The Year of Living Biblically is part Cliffs-Notes to the Bible, part memoir, and part look into worlds unimaginable. Thou shalt not be able to stop listening.

Introduction

As I write this, I have a beard that makes me resemble Moses. Or Abe Lincoln. Or Ted Kaczynski. I've been called all three.

It's not a well-manicured, socially acceptable beard. It's an untamed mass that creeps up toward my eyeballs and drapes below my neckline.

I've never allowed my facial hair to grow before, and it's been an odd and enlightening experience. I've been inducted into a secret fraternity of bearded guys -- we nod at each other as we pass on the street, giving a knowing quarter smile. Strangers have come up to me and petted my beard, like it's a Labrador retriever puppy or a pregnant woman's stomach.

I've suffered for my beard. It's been caught in jacket zippers and been tugged on by my surprisingly strong two-year-old son. I've spent a lot of time answering questions at airport security.

I've been asked if I'm named Smith and sell cough drops with my brother. ZZ Top is mentioned at least three times a week. Passersby have shouted "Yo, Gandalf!" Someone called me Steven Seagal, which I found curious, since he doesn't have a beard.

I've battled itch and heat. I've spent a week's salary on balms, powders, ointments, and conditioners. My beard has been a temporary home to cappuccino foam and lentil soup. And it's upset people. Thus far, two little girls have burst into tears, and one boy has hidden behind his mother.

But I mean no harm. The facial hair is simply the most noticeable physical manifestation of a spiritual journey I began a year ago.

My quest has been this: to live the ultimate biblical life. Or more precisely, to follow the Bible as literally as possible. To obey the Ten Commandments. To be fruitful and multiply. To love my neighbor. To tithe my income. But also to abide by the oft-neglected rules: to avoid wearing clothes made of mixed fibers. To stone adulterers. And, naturally, to leave the edges of my beard unshaven (Leviticus 19:27). I am trying to obey the entire Bible, without picking and choosing.

To back up: I grew up in an extremely secular home in New York City. I am officially Jewish, but I'm Jewish in the same way the Olive Garden is an Italian restaurant. Which is to say: not very. I attended no Hebrew school, ate no matzoh. The closest my family came to observing Judaism was that paradoxical classic of assimilation: a Star of David on top of our Christmas tree.

It's not that my parents badmouthed religion. It's just that religion wasn't for us. We lived in the twentieth century, for crying out loud. In our house, spirituality was almost a taboo subject, much like my father's salary or my sister's clove-cigarette habit.

My only brushes with the Bible were brief and superficial. We had a next-door neighbor, Reverend Schulze, a kindly Lutheran minister who looked remarkably like Thomas Jefferson. (By the way, Reverend Schulze's son became an actor and, oddly enough, went on to play the part of the creepy priest on The Sopranos.) Reverend Schulze told great stories about college sit-ins during the sixties, but whenever he started talking about God, it just sounded like a foreign language to me.

I attended a handful of bar mitzvahs where I zoned out during services and spent the time trying to guess who had bald spots under their yarmulkes. I went to my paternal grandfather's funeral, which was, to my surprise, presided over by a rabbi. How could the rabbi eulogize a man he'd never met? It was disconcerting.

And as far as childhood religion, that was about it.

I was agnostic before I even knew what the word meant. Partly, it was the problem of the existence of evil. If there is a God, why would He allow war, disease, and my fourth-grade teacher Ms. Barker,...