Returning to the chapel won't be a piece of cake, because Garrett will run into several new monsters. Luckily, you won't be forced to eliminate local beasts (but it's possible, especially that you won't need arrows any longer) but you have to be very careful. Enter The Dawn's Light - Stowage Deck again, wait until the first monster goes left and head in the opposite direction.
Stop next to the new monster and again wait until he shifts his position. Another creature stands next to the exit from the first level. Despite what you may think, you can pass it very quickly, of course if it's not alarmed and you use your slow moving mode. If you don't want to risk, you can try to lure out this monster throwing the items, but it shouldn't be necessary.
On your way to the chapel you meet another monster, but you can pass him without any problem. Enter The Dawn's Light - Chapel and walk towards Erin. You get to the final part of the chapter and begin another untypical boss fight.