I feel like you're playing the game very wrong if you needed to grind on EASY mode of all things, the game making your character cum a lot is intentional but you should still be able to defeat most enemies just fine without losing much spirit. I've beaten everything in the temple at around level 60-80, I think, and the Church purge costs became negligible (compared to earnings) after progressing far enough into the game. I think on both of my playthroughs, that point was after clearing the Forest Dungeon.
Are you targeting enemy weak points? Are you using status effects/buffs/debuffs to your advantage, like charm or sleep? Do you remember to use your inventory?