Religion

[Grammarsalad]

This one has developed significantly. Instead of Religion, it's going to be Ritual, and the description is roughly:

This non-weapon proficiency represents training in religious, spiritual, mystical, martial or traditional rites allowing characters to draw upon their inner strength or various forces in the world to perform amazing feats. In order to perform a ritual, characters must make some kind of sacrifice, which is often material or personal. Certain rituals require specific materials, and many rituals strain the body or mind, inflicting damage or reducing fatigue of practitioners.

Perform Ritual

In order to perform a ritual, a character must meet the prerequisites necessary to perform that ritual. Often, special materials, a certain number of ranks in the ritual non-weapon proficiency, or membership of a particular class (or spellcasting class) are required.

Example rituals with requirements:

Warpaint: You apply war paint to yourself in anticipation of battle.
Requirements: Ritual: 1 rank; war paint. Class/Kit: Barbarian, Shaman, Berserker or Ranger only. Cost: 1 war paint Bonus: +1 Melee damage, +1 saves vs. spells for 1 turn

Practice: You take a round to perform a few deadly maneuvers with your primary weapon.
Requirements: Ritual: 1 rank; Class/Kit: non-Barbarian, non-Berserker or non-Ranger warriors only. Cost: x fatigue Bonus: Cost: 1 war paint (20 gold?) Bonus: +1 strike/damage for 1 turn

Bless Water: You give a moment of thanks to your deity as you bless a vial of water.
Requirements: Ritual: 1 rank; Class/Kit: non-evil cleric or paladin Cost: 1 vial (20 gold?) Does d6/rank damage to undead and evil outsiders.

[Grammarsalad]

May call it ' faith', or perhaps better 'theology'. Nope: Ritual Definitely Theology, or Religion, or similar