"I know there are some scenes that are pretty graphic," Kelsey told ET. "I think the beheading of John the Baptist is pretty serious."
Killing Jesus is based on the bestselling book by Bill O'Reilly and Martin Dugard, which centers on the history and conspiracy surrounding Jesus' life and death.
"He was very intense and confrontational at the end of his life," Bill told ET. "Jesus was a revolutionary. He really was angry, but it was a righteous anger."
Kelsey, who describes himself as a religious man, said his faith had nothing to do with his decision to play the part.
"I read the part and thought, 'Wow, I'm gone by page 8, I think. Ok, why not?'" Kelsey said.
One plus to filming was that it offered him a chance to travel. The telepic wrapped shooting in Morocco in November.
The movie also stars True Blood's Stephen Moyer as Pontius Pilate, Entourage's Emmanuelle Chriqui as Herodia and 24's Haaz Sleiman as Jesus. The movie has faced criticism for casting Haaz because he is a Lebanese actor raised as a Muslim, but he responds to his critics by quoting the Bible.
"If you really look at Jesus and what he says, 'Love your neighbor as you love yourself,' so how could you then say it's teaching you to be hateful to someone else who's different from you?" Haaz said.