(RNS) What I actually know about God might, on a good day, fit on a quarter of the head of a pin compared to the fullness of God’s true hugeness.

That said, there are a couple of things about the Almighty that I’m pretty certain are true.

God’s grace is always staggering and often surprising. And God has a tremendous sense of humor.

Case in point: Second-hand socks.

I happened upon this odd epiphany while reading a simply beautiful (and beautifully funny) new book, “Thrift Store Saints: Meeting Jesus 25 Cents at a Time” by first-time author Jane Knuth.

Fifteen years ago, Knuth — a baby boomer, cradle Catholic, teacher, wife and mother — walked into the St. Vincent de Paul Society thrift shop in Kalamazoo, Mich., hoping to purchase a rosary for her daughter’s First Communion. When she tried to pay with a credit card, she learned the store only took cash or checks.

“Everybody takes credit cards,” she thought to herself. “McDonalds takes credit cards!”

Knuth complains bitterly about the stores “lousy” hours and the inconvenience. Dorothy, the white-haired saint at the register, tells her sweetly: “Most of our customers don’t have credit cards. So it’s usually not a problem.”

Dorothy’s words, and her subsequent kindness toward a not-so-gentle giant who angrily demanded a new pair of shoes to wear to church, shocks the author into realizing that she is not standing in a simple thrift store. She’s in a sacred place.

Knuth has been volunteering at the St. Vincent de Paul Society store ever since.

Recalling one of her earliest days at the shop, Knuth says: “Those three people standing outside aren’t problems to be solved — they are my teachers. They aren’t going to mug me — they’re going to show me the way to God.”

The St. Vincent de Paul Society is a worldwide Catholic organization founded in Paris in 1833 with the express purpose of meeting the physical needs of the poor by going to them and offering help.

“Don’t make the poor ask for what God, their Father, wants them to have,” St. Vincent said. “We should apologize if they have to ask for what they need.”

Votaire said God is a comedian who plays to an audience that is afraid to laugh. Thankfully, Knuth isn’t afraid to laugh, sharing her God stories in breezy, eloquent prose with ample self-deprecation and great humor.

Knuth finds herself in many unexpected places and situations where she meets the living and loving God.

There was the time Knuth went to meet a client at a big box retail store where the woman worked a second job as a greeter. The woman has no break, so Knuth pulls out a pen and fills out some paperwork herself, lobbing questions at the harried single mom who answers dutifully without missing a beat.

“I’m going to need your landlord’s name and phone number…the last four digits of your Social Security,” Knuth begins.

“Have a nice day! His name is ———— and he lives on ——–,” the woman answers. “Have a nice day! And my Social Security number is ————. Need a cart today, miss?”

Another time, the local hospital calls the thrift shop, looking for help in delivering a bed to an older female patient who’s being released after a debilitating illness. Could the Society help?

Knuth and her husband, Dean, deliver the bedroom set to the ailing woman’s home in a dodgy neighborhood, meeting drug addicts and would-be thieves along the way. As they leave, the woman tells them she’s never had a bed of her own.

In her charming book, Knuth indulges neither the cute nor the contrived. Her stories ring true precisely because they are full of the kind of imperfect details that make life what it is. Messy. Surprising. Maddening. Blessed.

Which brings me back to second-hand socks.

Tim is a regular at Knuth’s store. He’s young, fresh-faced and rides his bike everywhere. Knuth first met Tim as he stood at the register, trying to decide between purchasing a plastic change purse or a pair of (used) socks.

Each item cost 25 cents, but he didn’t have enough on him for both.

Refusing to take the socks with him and pay on his next visit, Tim pedaled to his bank and came back with a quarter.

“Blessed are you who are poor,” Knuth writes, recalling one of the Beatitudes, “for the kingdom of God is yours.”

(Cathleen Falsani is the author of “Sin Boldly: A Field Guide for Grace” and the recent book, “The Dude Abides: The Gospel According to the Coen Brothers.”)