The Devout is one of the endgame jobs of Final Fantasy III. It is behind the Earth Crystal, alongside the Summoner and the Magus.
The Devout is the "advanced" version of the White Mage job: It can use Tier-8 spells and their previous tiers have far more charges.
In the original Final Fantasy III, Devout comes at a somewhat awkward time. The job is located in the Ancients' Maze, right before the Crystal Tower
Due to the Sage being nerfed to be on more equal footing, the remake's rendition of the Devout gets more use. However, while it is a straightforward upgrade to the White Mage, it still starts at Job Level 1, meaning that leveling the job level will be necessary to get the full benefit. Thus, how hard it outclasses the white mage is somewhat up for debate.