An Ottawa heavy metal bar will host The Satanic Temple Canada’s Ottawa chapter Saturday in an invitation-only ceremony called an un-baptism.

Fifty people are expected to attend the unprecedented "black mass" ceremony at Koven Restaurant in the ByWard Market. Organizers said the ceremony is the first-of-its-kind event in Canada. Followers of Satanism argue they will be practicing their faith much like other religious groups do on weekends.

“We use the idea of Satan symbolically, it has a lot of deeply-held meaning to us because a lot of us have identified with that sort of anti-hero character for a long time,” said Satanic Temple Ottawa chapter member Nicholas Marc.

Ottawa’s Archdiocese, however, has expressed concern with the Satanic Temple event, calling it blasphemous.

"My concern is for the faith of our people and the offence that this brings. A "black mass" is vile and sacrilegious, attacking the most sacred reality of our faith, the consecrated host: The body, blood, soul and divinity of our lord Jesus Christ," said Archbishop Terrence Prendergast, who said in a statement provided to CTV News, “We need to pray in reparation for the spiritual harm that is being planned, and that God would turn this blasphemous project into an occasion of grace.”

Marc said his religious group has every right to practice their faith and is in no way a threat to Catholicism or any other religion. Marc added the rituals do not promote hate or cause harm.

“I think if people have faith in their Catholicism or their Christianity or whatever they have faith in then they shouldn’t be worried someone else is going to come along and threaten that; they should feel secure in the history and tradition of their faith as we are,” said Marc, who started practicing Satanism 3 years ago.

“What we're doing right now is asserting our constitutional right, our religious right, even though it may make people feel uncomfortable, we're not hurting anyone, we're not targeting anyone. This is for us, by us, end of story.”

The owner of the space, who said he has faced many threats for hosting the event, believed the controversy has very little to do with religion and more to do with promoting democracy and free speech. Back in his home country of Iran, he said, a heavy metal band was subjected to 74 lashes and 14 years in prison because of the music they play, which is considered blasphemous in Iran.

“One of the reasons people come to Canada is because it's a secular country and religion and state are separate,” said the owner of Koven, who wished to withhold his identity over fears for his safety after having received letters and calls from concerned Christians asking him to reconsider hosting the event.

“They just call and say ‘Oh, this is bad. You shouldn’t do this. This is sacrilegious’,” He said his reply remains unchanged, defiant, but respectful. “They're not hurting anyone. They're not doing anything to harm anyone.”

Marc and the Satanic Temple have vowed this won't be their last ritual.

“It has nothing to do with the Catholics or Christians; we are Satanists practicing our satanic faith,” he argued.  ““All we're going to be doing Saturday is practicing our faith, in private, on our own terms, like every other religion does,” said Marc.