"There were times they almost called it quits," a source tells OK!, noting that the duo — who are worth a combined $165 million — have endured cheating rumors, a love child scandal and McGraw's battle with sobriety.
Now, the source says they've nixed any plans for a divorce: "They didn't want to become another statistic, so they fought to make it work."
The pair hit a serious rough patch over a decade ago. "Tim was boozing, flirting with women and acting like a total jerk to Faith, who was raising their three daughters and getting increasingly frustrated," spills the source, adding that the pair also clashed over McGraw's suspected infidelities. "Faith finally drew a line in the sand and gave him a choice: It's either alcohol or your family. Tim quit drinking cold turkey. He didn't want to lose Faith."
Things got rocky again in 2013 when rumors swirled that McGraw, 54, had hidden a secret son from Hill, 53. (According to reports, Tim quietly kept in touch with ex-fiancée Kristine Donahue and her now-grown child, Tyler Zarbo, after their split in the mid-'90s.)
"This was apparently news to Faith. She was upset and insisted Tim cut all ties," recalls the source. "The word is Tim [realized it] wasn't worth risking his marriage."
In the end, the bumps in the road have only brought them closer. "Tim's maintained his sobriety and is devoted to being the man Faith fell in love with so many years ago," dishes the source. "They've raised three strong girls, and the romance is still alive. In fact, they're talking about taking a second honeymoon, just the two of them, when they're able."
Adds the insider, "Tim and Faith have a lot to celebrate these days."