Tim Tebow is an N.F.L. quarterback, and Tim Tebow is an outspoken Christian.

And while quarterback controversies are almost as common as quarterbacks, who play perhaps the most scrutinized position in American sports, what has erupted around Tebow this season is altogether different.

At the intersection of faith and football, the fervor that surrounds both Tebow’s beliefs and his struggles in his second season for the Denver Broncos has escalated into a full-blown national debate over religion and its place in sports.

While Tebow is not the first openly religious athlete, the circumstances surrounding his performance this season are so unusual, the N.F.L. is experiencing a rare, if not unprecedented, religious feud. The latest chapter in the Book of Tebow played out Sunday, when he threw two touchdown passes in the Broncos’ upset of the Oakland Raiders, perhaps saving his status as the starter, but not ending the larger debate.

“The role religion plays here is enormous,” said Kurt Warner, the former N.F.L. quarterback and a similarly outspoken Christian athlete. “When somebody professes their faith, and I was that guy for a long time, people automatically think when you praise God it’s because He makes passes go straighter or helps win games. When you lose, they say, your faith doesn’t belong here. Your God’s not helping you win.”

To his most fervent supporters — and there are many — Tebow was never just a quarterback. He was a champion of Christianity in shoulder pads, a wholesome, fearsome football player who loved God and touchdowns, in that order. If detractors found Tebow preachy, if he seemed too good to be true, he still won two national championships and a Heisman Trophy at the University of Florida, securing his legend as one of the greatest college players ever.

Drafted last year by the Broncos, he played sparingly his rookie season. Now, his struggles to adapt to the N.F.L. have changed the tenor of the debate around him, made it nastier, more personal, more intense. Supporters have reacted to criticism of Tebow as an indictment on religion, while detractors seem to delight in every wayward pass.

Just last year, Tebow drew national attention for his antiabortion commercial broadcast during the Super Bowl. In the past three weeks, he has become the most discussed and most polarizing figure in sports, strange territory for a replacement player on a last-place team. Opponents mocked his celebration pose — kneeling, in prayer, which became an Internet meme known as Tebowing – and his coach offered a lukewarm vote of confidence.

One columnist in Denver called Tebow the worst quarterback in football. Another columnist in Canada labeled Tebow the “Kim Kardashian of sports,” for the intense reaction he elicited. Online, the torrent of mockery and criticism has been fierce. Blog posts included “God explains why he let Tim Tebow fail” and Twitter exploded in hateful vitriol, to which the Sports Illustrated writer Joe Posnanski mused: “I believe Tim Tebow isn’t an N.F.L. starter and I want him to prove me wrong because I believe he’s a great guy. Is that allowed?”

In sheer volume and intensity, the comments section on an ESPN article best captured the storm known as Tebow mania. They ranged from critical to crude under the theme “X is > Tebow,” with X being “eating your kids” among the options, as moderators struggled to delete the escalating venom.

“This isn’t so much about Tim Tebow,” said Lincoln Blumell, an assistant professor of ancient scripture at Brigham Young University and a former college quarterback. “This is about people and about religion in sports.”