Yeah pretty much what Key said about the GBA games, (And Gamecube?)
I don't recall any mention of gods or goddesses,
I do recall that monk, priest, Cleric, and bishop characters follow saints, kinda like in a catholic kinda way. (I think.)
Yeah, and as far as black magic, you only get one character in both GBA games that can use it.
You do get quite a few characters that can use color/nature magic, but you can always not use them like Key said.
(There are plenty of weapon characters. ^-^)
, as for Fire Emblem: Awakening... (The 3DS Fire Emblem)
Well... quite a bit has changed...
Quite a few characters say "gods" as a swear word, (quite often to.)
so there is mention of quite a few gods, but only two are named:
there is an evil dragon called grima that some call a god,
and you also get a monk that believes in a goddess called naga. (naga is mentioned through out the game.)
Though as a little spoiler you do actually meet naga near the end of the game,
and kinda surprisingly this came up during the conversation,
Naga: ...But know this: I am no god.
Then after someone else says something,
...I am no creator. I possess not the powers of making or unmaking. And neither does Grima. Neither of us bears the power to destroy the other utterly.
Though they are still called gods throughout the game. -.-'
As for black magic,
you get two characters, which you can use an item to switch their class to something non-black magic.
Though unlike the GBA black mages who use black magic from books, these black mages also use curses and hexes.
Only the book based black magic is used in battle,
but in their support conversations they pretty much mention them every time.
(Which is quite disturbing to say the least.