Rules aren't so strict for a roommate ad.I'd probably not mention religion at all.

Housing discrimination based on race, color, national origin, religion, sex, family status, or disability is illegal by federal law (HUD Discrimination).

People who want to promote their brand of religion, but no others, are their target.The people associated with the Satanic Temple are mostly atheist (don't believe in God or Satan) or agnostic (still searching for the truth) at best.

Christians with ethics and integrity don't generally seem to need to invoke their religion to prove it.  

I expect to be held to the same standard as any other GC no matter their gender, race, sexual orientation, religion or the host of other things people use.  

It says"To refuse to sell or rent after the making of a bona fide offer, or to refuse to negotiate for the sale or rental of, or otherwise make unavailable or deny, a dwelling to any person because of race, color, religion, sex, familial status, or national origin."

@Steve Vaughan thank you, no I dont believe in religion and I havent got much family.  

In DC I don't think you can ever legally discriminate in renting on basis of race, religion, familial status, or any of the other protected classes, etc., unless you actually live in the same house (for example, renting rooms to female students only).

Thomas S.As you acknowledged in response to Chris' post, you may not discriminate based upon nationality, ethnicity, religion, sex or sexual orientation, familial status, etc. in Canada.   

The Fair Housing Act The Fair Housing Act (the Act) prohibits discrimination because of race, color, religion, sex, national origin, disability, and\ familial status in most housing related transactions.