With the Rise & Fall expansion, purchasing combat units requires the Grand Master's Chapel built in your Government Plaza.

The Theocracy government allows land combat units to be purchased with Faith and also grants a discount to Faith purchases.

The Oracle Wonder reduces this cost by 25%.

Great People may be patronized (purchased instantly) with Faith.

Naturalists may only be purchased with Faith.

Worship buildings may be purchased with Faith.

Inquisitor (requires Launch Inquisition).

The primary use of Faith is to purchase Religious units:.

Stonehenge is an early game wonder which rewards a Great Prophet to start a religion but the Wonder can only be built adjacent to Stone. To get a Great Prophet a player has to aim for Great People Points.

A Religion is Predominant if it is followed by more than 50% of the cities in a civilization. To achieve a Religious Victory your Religion must become the Predominant Religion for every Civilization in the game. Faith is used as an alternate currency to Gold and can be used to purchase religious units like an Apostle, Great People, special buildings, and in Theocracy Government can purchase land combat Units. Once a Civilization reaches a certain amount of faith, it gains access to a Pantheon which gives bonuses for their entire empire. Faith can be spent on Religious Units, depending on the Era of the game. Faith is accumulated per turn, as dependent on all sorts of things throughout the game, Buildings, Wonders, Great People, as well as Tile Improvements, Natural Wonders and a few other things. Faith is one of the more advanced Game Concepts in Civilization VI, which contributes to what makes the Religion part of your Civilization grow.

How to use inquisitor civ 5