I used to be athiest
This is the one thing i dislike about it. The zones in world 2 are much longer than in world 1 and you lose your progress if you leave halfway through. Im dreading attemping trib mode on world 2.
Not to mention i spent ages yesterday killing all the assassins in zone 2 and i didnt get the achieve. I can only assume i missed one assassin in some really well hidden spot near a hidden room or something, because I was careful to check everywhere along the route.