The Brethren were the founders of the town of Silent Hill, and most of the town’s buildings carry the cult’s symbol, a sign of the townspeoples’ devotion to their religion. Because the cult was so powerful during the town’s heyday, they were able to get away with actions that were reprehensible or illegal, such as abusing a young child and hanging a painting of a woman being tortured in the local hotel.
The Brethren are directly connected to the current abandoned state of Silent Hill, having been the ones responsible for setting the blaze that ate into the coal mines beneath the town, setting the entire town on fire and leading to its permanent evacuation. Most, if not all, of the Brethren are either dead or trapped in an alternate reality
The cult appears to worship a female goddess, whose picture is seen in both the school and Dahlia Gillespie’s apartment. They seem to have mainly Catholic leanings, however, it has been stated by the creators that the cult is not related to any one religion. To that end, their symbol is a mixture of icons from different religions. The cult believes that sinful acts must be strictly punished, and that it is possible for females to become possessed by demons if she is associated with a sinful act. The cultists are shown to be obsessed with the concepts of Hell and damnation, even going so far as to etch the words “Heaven” and “Hell” on a child’s hopscotch drawing at the elementary school.
According to the canon of Silent Hill, the Brethren stand in opposition to the Order, a fanatical cult seen in the game series who worship a pagan God. Jennifer Carroll, someone who was associated with the Order in the games, was burned alive by the cultists in the film, and her burning was memorialized in a painting that hangs in the Grand Hotel.
After the cultists are dragged into the fiery Otherworld, an alternate reality created by the rage of a child they had tortured, they refuse to believe that they are responsible for their own damnation. To that end, Christbella (the cult leader) misleads them, telling them that the Apocalypse has occurred, and that they were the only ones pure enough to survive the devil’s wrath. The Brethren believe that their prayers hold back the darkness, when in reality, the coming and going of the Otherworld is in no way affected by their beliefs.