Songs by Christian artists are nothing new to professional sports, but there has certainly been an uptick in their presence over the past few months. Now, one mixed martial artist is making history--and causing controversy--with his walkout song selection. 

When Vitor "The Phenom" Belfort "fights Ronaldo "Jacare" Souza in Brazil next month, fans will be hyped into a frenzy as he enters the room to the song "Battle Cry" by The Kingsmen. (WATCH HERE.)

Belfort, an outspoken Christian, said he wanted to find a song that both captured the passion of the fight and the heart of his spiritual beliefs. 

"I listen to this and I just get pumped," Belfort told MMA website Bodog. "I know it will put me in the right mindframe to continue to be successful inside the ring--as well as outside it."

Belfort recently debuted the new song in a special middleweight exhibition fight in Las Vegas last month. 

Not everybody is pleased with Belfort's decision to use the Southern Gospel song. A number of his opponents have filed complaints with the UFC, asking the organization to ban the use of "Battle Cry" on fight night.

"Their primary concern is that it can create a vibe in the room that will give an unfair advantage to Belfort," a spokesman for the UFC told NRT. "That kind of song in that kind of place can yield unpredictable results for opponents. Studies show that Southern Gospel turns some men into superheroes, while it can bring others to their knees in submission before even the first bell rings. To have that element in play, all the while Vitor is empowered and strengthened unfairly, certainly brings cause for concern."