Rather than use things like prayer mats, altars, bread, wine, profound music, sermons, and singing to convey their devotion, obstructionists prefer materials like brick walls, huge piles of junk, roadblocks, large trees, opaque windows, and doors with hinges on both sides. Obstructionism believes these objects are holy, but understands that the objects may be damaged or destroyed by frustrated people who are unable to get by. For this reason, the heavier and more indestructible an object is, the holier it is.