December 08, 1997 12:00 PM

IT WAS A BRILLIANT SPRING MORNING, and Gladys Knight was about to sit down in her airy, six-bedroom desert home outside Las Vegas to write the concluding chapter of her life story. She had looked forward to this moment for months. Though she had suffered through two disastrous marriages, Knight, 53, envisioned a happy ending—to her life and to her book—thanks to husband No. 3, Les Brown. Her two-year marriage to the popular 52-year-old motivational speaker, who was out of town on a speaking tour that day, had seemed, for a time, a dream come true.

But before she could pick up her pen the doorbell rang; she opened her front door to face a nicely dressed couple. “The man and woman were process servers,” she writes in her newly published autobiography, Gladys Knight: Between Each Line of Pain and Glory (Hyperion). “They handed me divorce papers that had been filed by Les.”

Knight is no stranger to the blues—on or off the stage. Best known as the rock and soul diva who, with the Pips, wowed audiences in the ’60s and ’70s with now-classic crossover hits such as “Midnight Train to Georgia,” in private she has experienced more than her share of anguish. Of Brown, she says today, “God has given him the gift to verbally motivate and inspire, but he doesn’t know how to give.” Knight does admit, however, that conflicting schedules often kept them apart, and she even thanks Brown, who urged her to write the book and helped her to land a reported $500,000 advance. Then, too, he provided the book with a gritty conclusion. “Fairy-tale endings, after all,” Knight writes in her last chapter, “only happen in fairy tales.”

And Gladys Knight’s story is anything but. Although famously immune to the drug and alcohol epidemic that did in so many rock idols, she reveals that for nearly a decade she was hopelessly addicted to gambling. She liked to bet on football games (“If I wasn’t betting, I wouldn’t watch”), but her cash-consuming passion was baccarat. Hooked on the game since the late 70s, Knight would regularly win or lose tens of thousands of dollars at a single sitting. In the late ’80s, after a high-stakes binge that lightened her pocketbook by no less than $45,000, she bottomed out. “It was something I really enjoyed,” says Knight, who believes she has kicked the habit with the help of Gamblers Anonymous. “I would play every day if I could. All I know is I woke up one day, and it was out of control.”

Well aware of the impact the book will have on her image as a self-described Miss Goody Two-shoes, Knight says her aim was not to shock fans but to demonstrate “that I’m not perfect. None of us are.” Among the revelations: Knight became pregnant at 16 only to lose the baby in a devastating miscarriage after marrying the father, a sweet but struggling Atlanta musician named Jimmy Newman. Though she calls him the love of her life, she writes that Newman became a drug addict and abandoned her and their two young children when Gladys was just 20. Her second marriage produced her third and youngest child, Shanga, now 21 and a college senior in Atlanta, but ended in a long, bitter divorce and custody fight.

Of course, Knight has enjoyed her share of glory as well, most of it stemming from a rare vocal talent first revealed when she soloed at age 4 at the Mount Mariah Baptist Church in Atlanta, where she was born. Shortly after appearing on the Ted Mack Amateur Hour in 1952, 8-year-old Gladys formed the Pips, named after a cousin’s street handle, with older brother Bubba. When their late, beloved father, Merald, an Atlanta postal worker, suffered a nervous breakdown, then 13-year-old Gladys had to help support the family.

The group’s grueling apprenticeship finally paid off in 1967 when “I Heard It Through the Grapevine” climbed to the top of the pop charts. A string of hits followed, along with Grammy Awards in 1973 and 1988. Last year she and the Pips, who split in 1989 when Knight launched her solo career, were inducted into the Rock and Roll Hall of Fame. This Feb. 26 she and Bubba, who also lives in Las Vegas and works as her road manager, and cousins William Guest, who lives in Detroit, and Edward Patten, who is recovering from a stroke in Atlanta, will reunite to receive the 1998 Lifetime Achievement Award from the Rhythm and Blues Foundation in New York City. “I’m really happy about it,” says Bubba. “It’ll be the first time we’ve been together as a group in years.”

A resident since 1978, Knight has no intention of leaving Las Vegas, gambling addiction or no. To help her resist the lure of casinos she relies on the spiritual lift she gets from her newfound Mormon religion (born a Baptist, she converted recently from Catholicism), as well as the support of her close-knit family. Her mother, Elizabeth, 80, son and manager Jimmy Newman, 35, and his wife and five children live nearby, as does her daughter Kenya Jackson, 33. In 1993, Gladys and Kenya, a mother of five, opened Kenya’s Gourmet Bakery, the most successful wedding-cake emporium in town. Six months ago they launched Kenya’s Cakes of the Stars, a second bakery that sells cakes named for Gladys, Patti LaBelle and longtime friends Dionne Warwick and Natalie Cole, who are all investors in the business.

Single again and thriving, Knight dotes on her 10 grandchildren and performs regularly at Vegas casinos. She’ll mark her 50th year in showbiz next year by releasing a CD of gospel tunes. And though she has now been thrice burned in marriage, “I haven’t given up on love,” she says. “I’m a glutton for life.”