In chapter 3 of The Lilies of the Field, Homer takes the German nuns to a Catholic church in a shabby little town called Piedras. Homer still hasn't built the nuns their new church, so in the meantime, the best he can do is to take them to an existing place of worship.
After the Mass has ended, a priest by the name of Father Gomez shows Homer around the church; this is the first time that this staunch Baptist ever been inside such a place. Though still repelled by Catholic ritual, Homer does at least find the church interesting from an architectural standpoint. There's a certain ramshackle quality about the place, a simplicity one doesn't often associate with Catholic churches, that attracts Homer. He understands poverty, and this simple little church in a one-horse town positively screams it.