No, its not. There are activities permitted in certain zoned locations. If a neighbor complained because an "AVERAGE" of 15 people were coming over 2 times per wk and taking up every parking spot and making a racket chanting and singing then the authorities are charged with investigation. Part of that investigation is to ascertain what is happening to lead to the complaint. If an organized prayer fest is going on 2 or 3 nights per week and zoning says churches and religious activity is confined to commercial zoning then they are perfectly within their means.
And why does this have to be about Christians? Wouldn't the neighbors complain equally if they were inside chanting to jabooty? Yes.