Creeds in Salt and Sanctuary are factions that the player can align with to bestow certain benefits and different NPCs in their Sanctuaries through the use of Offerings. NPCs will sell different gear depending on the Creed. Some Sanctuaries are occupied by Creeds that are different from your own, where you cannot make Offerings without desecrating them with a Stained Page or by using a Crystal Sphere to convert them; however, you can still level up and view the Tree of Skill. Desecrating a Sanctuary of another Creed will give you Sin and will turn any NPCs in the Sanctuary hostile to you. You will also have to defeat multiple waves of difficult enemies (which for now are being called Sanctuary Guardians) before you are able to convert the Sanctuary to your Creed and use its services. Abandoning a Creed for another makes you an Apostate. There are 7 Creeds in Salt in Sanctuary. Endings are affected by your Creed.
Devotion & Sin
Creeds have Devotion. To raise your Devotion level, you must turn in remains from Enemies to a Stone Leader. Each time you raise your level of Devotion with a Creed, you will be able to select from a list of items of your choosing as a reward to the player. These items act the same as HP or Focus potions and can be replenished at a Sanctuary belonging to that Creed. Additionally, NPC vendors will start selling new items. The max level of Devotion is 7.
If you choose to leave your character's Creed to join another, you will gain Sin and become an apostate to the Creed you left. You will lose access to some of the Creed's NPCs' services and also lose your Devotion to that Creed.
Desecrating a Sanctuary by using a Stained Page will give you Sin and make all sanctuaries of that creed hostile toward you. You will be unable to teleport to any of that creed's sanctuaries and you will be attacked upon entering. You can not desecrate a Sanctuary of your own Creed.
You must forgive your sin by visiting The Candlelit Lady for Creeds you have desecrated to cease their hostility, and to be able to rejoin Creeds you are an apostate of.