Restoring the Faith is a quest in The Waking Shores.
Restoring the Faith Quest Guide
Wrathion rather impatiently asks you to help him finish repairing the Oathstone. Speak to him at 27.29, 62.56 and then watch the cutscene. After the cutscene, interact with Wrathion at 27.07, 62.18 to fly with him up to the Obsidian Throne. You can speak to him again at 24.44, 55.53 to complete the quest.
Restoring the Faith Quest Start
Restoring the Faith is started by speaking to Forgemaster Bazentus at 24.68, 61.11 after completing The Spark.
Restoring the Faith Quest End
Restoring the Faith is completed by speaking to Wrathion at 24.44, 55.53.