Taking a player corpse out of the church is not a PvP action, unless the intent is to hide it or damage it to badly impaired.
I'm uncertain of this, as I've always been told that moving a corpse after it has been placed somewhere is going against the rules. And even as I have picked up a corpse seemingly in the middle of the road with the intention of reviving the character, I was immediately contacted by a DM curious what I was doing with it.
I'm not convinced you can take a corpse out of there at all. First being ignoring NPCs that you just, taking a corpse and secondly because of mechanical rules.
The last time this debate was brought up, the DM response was as Aprog pointed out, despite it flying in the face of all reason that removing corpses from the temple isn't an 'ignoring NPCs' rulebreak, regardless of the intent behind the corpse's removal. From an in-character perspective, those remains are held by the Morninglordian faith to ensure that they aren't defiled until either they are revived, or buried and presented with final rites. But as the example was given previously; there's zero recourse for even a Morninglordian PC to intervene if someone walks in and just starts taking bodies.
Given that the possibilities for what a person
can do with a body is; removing it to another area, which is in all forms 'hiding the body', or to feed on the remains which is only a rulebreak if they badly impair the body. Even if they
did impair the remains and that's a PvP action, the most that's required is for them to hostile the character the remains belong to if they are online. Furthermore, if someone does steal a body and then feed on it, they're very unlikely to actually return it afterwards because if anyone's witnessed them pick up the body and then bring it back half an hour later, they're going to wonder what the hell they were doing with it.
TL;DR, removing bodies from the ML Temple or any other similar place is not a rulebreak, even when it
should be.