"I tell people all the time, 'Gwen saved my life last year,'" Shelton says in a new interview with CMT's Hot 20 Countdown. "She did, and I think she would probably tell you something similar about me."
While fans immediately embraced the couple when they made their relationship official, many also were left scratching their heads about what the country singer, 39, and his new rocker girlfriend, 46, had in common.
"It's not something that anybody could have seen coming, besides God, I guess," says Shelton, who split from Miranda Lambert last summer. "It doesn't look like it makes sense, you know? But all I can tell you is, it does, it just makes the most perfect sense for us and where we're at in our lives."
The couple's relationship turned romantic last fall, and Shelton acknowledges the sudden spark took even him by surprise.
"Even coming into [her] second season [working on] The Voice, I didn't even really know her that well," he says. "All of a sudden this thing just happened because of some things we were going through and it saved my life, period."
The "Came Here to Forget" singer's tenth studio album If I'm Honest is out Friday.