What says that the right way to hold the dagger and scabbard is not the other way around so the church is right side up and the satanic priestess is upside down? In which case it would be the church triumphing over paganism, satanism and the like.
So far no one has presented an overturned church (spires, portals crosses and all) and this is the first time I see architectural features portrayed on a scabbard. Interesting it would be to find precedent for architectural depictions and see how they are done. If a castle were shown in the manner of this church, would the dagger indicate a political movement/rebellion? Architectural depiction usually has the problem of having to fit the shape of the space it occupies. A triangular building in a triangular shape will most times prescribe only one way to arrange it.
I think the "right way to hold the scabbard" is too ambiguous in some cases. If there were separate symbols following one alignment and one were overturned, then a case could be made. But when there is only one apparant symbol, what is there to indicate the "right side up"? Looking at examples from different places won't help either IMO. Maybe a German will look at it this way, a Frenchman that way, a Brit another and a Spaniard yet another...the Italian will laugh at them and show the right way
Emanuel