Former NFL star Tim Tebow has such a strong Christian faith that it's surprising to hear that the kind-hearted athlete also deals with spiritual doubt from time to time.

In his new book "Shaken: Discovering Your True Identity in the Midst of Life's Storms," Tebow reveals that his faith got rocked after he was cut from the New England Patriots back in 2013. Tebow recalls that before his former Denver Broncos coach Joshua McDaniels and head Coach Bill Belichick sat down with him to share the bad news, he actually thought he would be continuing with the team.

"Sometime earlier, Robert Kraft, the owner of the Patriots and a man I respect and really like, had told me he was looking forward to seeing me at his get-together the next day," Tebow's book reads, according to The Christian Post. "He was hosting a barbecue for the team and the staff at his home. Thinking about his words, I felt like it was a good sign."

So when McDaniels and Belichick broke the news, Tebow felt like he just received a "sucker punch."

"I didn't see it coming," he says. "I shifted my thoughts toward God, the One I believed had led me to New England. I thought this was going somewhere special."

Tebow asked God, "I thought this was a plan You designed for me. If that was true, then why, God, why is this thing crashing and burning?"

But despite this moment of weakness, Tebow came to the right realisation: God will always be with him no matter what direction his life might take.

"I knew God hadn't left me. I knew He still had a plan for my life," he says. "I knew He still had a purpose. And though my foundation in Him was solid, much of what rested on top of that was shaken."