One of the game's top players -- rushing for more than 1,000 yards in six of his seven seasons and topping 2,000 yards in his 2012 league MVP season -- Peterson called the death of his 2-year-old son in October a reality check for him.
He learned only two months earlier that he was the boy's father and had been planning to meet him before the boy died Oct. 11. Joseph Robert Patterson, who was dating the boy's mother at the time, was charged with murder and manslaughter after he allegedly assaulted the child.
"It's just made me stop taking things for granted," Peterson said in a recent one-on-one interview with ESPN.com. "Life is short. You never know. You just want to take advantage of the time you do have."
Peterson proposed to his longtime girlfriend, Ashley Brown, on July 4, and the two were married July 19. The couple has one child together -- 3-year-old Adrian Jr. -- and Peterson said he is more careful to cherish his time with the four children who don't live with him.
Before his son's death, Peterson had already begun meeting with a pastor, Calvin Simmons, who ministers to athletes through an organization called National Athletic Pastoral Care, for weekly Bible study that eventually led to premarital counseling as Peterson prepared to propose to Brown. He said he realized during that process that he needed to commit to one woman and live in accordance with his Christian beliefs.
The death of his son, Peterson said, served to reinforce the conclusion he had drawn in his mind about, among other things, stability and commitment.
"It's time for you to really get your life in order," Peterson recalled telling himself. "When all that stuff came down, it's more like, 'Reality check, man.' It's time to start walking the way you know you need to instead of straddling the fence -- knowingly straddling the fence.
"First and foremost, [it was] getting in alignment what God wanted for me in my life and stop [being promiscuous]. I was pretty much doing what I wanted to do, and I could pretty much do that. [It was] just to get in alignment with God, having a wife and really creating that bond and that life. It was more fulfillment knowing the head man is proud and knowing I'm doing it the right way."
Peterson credited former Vikings coach Leslie Frazier with helping him make changes in his life, calling Frazier a "spiritual mentor."
He was perhaps the Vikings' most outspoken player in defense of Frazier, who was fired Dec. 30 after a 5-10-1 season. But since then, Peterson said, he has realized no matter his personal relationship with Frazier, new coach Mike Zimmer is a better fit for the team.
"It was good to have him there, Coach Frazier, but [Zimmer] fits our players better," Peterson said. "That's something I can honestly sit here and say. A lot of guys can't respond to a Coach Dungy, Coach Frazier, guys like that. A lot of guys respond to Coach Zimmer. He's a better fit for the team."
Peterson turned 29 in March, but he believes he is nowhere near the precipice over which many running backs tumble at that age. And away from football, his life has a more focused purpose.
"I just feel like he's grown up," Brown said. "He's just matured into the man he's meant to be. You're very young when you first get in the NFL, and he went through that whole phase, being a young man, being new in this arena. Within the past year or two, he's calmed down so much. He's matured very much. He's just kind of grown into the man of God he should be."