The impurity you harvest from your own flock, the Sins of the Flesh currency that fuels breeding, fleeces, and darker rituals.
Sin is the currency you make by corrupting your own followers and then absolving them of it. Added in Sins of the Flesh, it powers breeding, special fleeces, and the game's most sinister rituals, but harvest it carelessly and your followers turn on you.
It is a mid-game unlock. According to the wiki, Sin becomes available after you defeat the third Bishop and perform a sermon, which opens the Sin Doctrine path.
The catch is Damnation. The wiki notes that absolving a follower of Sin has a chance to turn them into a Damned follower who flees the cult, so how you farm Sin matters.
This guide covers how to unlock Sin, every way to farm it, what you can spend it on, and how to avoid creating Damned followers.
A currency from Sins of the Flesh, harvested from your flock.
Beat the third Bishop, then hold a sermon.
The Mating Tent, to breed followers.
Damned followers if you over-harvest one follower.Sin is a separate currency, not a stat. Per the wiki, it is the manifestation of your flock's impurity, a resource added in the Sins of the Flesh update and earned by maxing a 
follower's Sin bar and then absolving them.
It unlocks after the third Bishop. According to the wiki, Sin becomes available once you defeat the third Bishop, and performing a sermon afterward triggers a cutscene and opens the Sin 
Doctrine path.
Followers fill a Sin bar as they indulge. The wiki explains that sinful actions fill a bar above a follower's head, and once full they must be absolved, handing you the Sin as currency.
Sin comes from a long list of sinful activities. Per the wiki, the core sources are the Rite of Lust, Rite of Wrath, and Gluttony of Cannibals rituals, each of which loads Sin onto a follower to be absorbed.
Passive sources add up too. According to the wiki, followers can confess daily for Sin after the Doctrinal Extremist teaching, drink at the Drinkhouse, perform at a Drum Circle, or be born with the Born of Sin trait.
Some sources are situational. The wiki lists the Temptation's Fate Tarot card giving enemies a 10% chance to drop Sin, defeating bosses with the Violent Extremist trait, talking to Furfur at a Sinner location in The Rot, and a follower winning a fight against a Snowlamb.
Rite of Lust, Rite of Wrath, Gluttony of Cannibals Confession, Drinkhouse, Drum Circle
Temptation's Fate Tarot, Violent Extremist killsSin's biggest job is breeding. Per the wiki, the primary use of Sin is selecting two followers to mate in the Mating Tent, and the Sin is spent even if the mating fails, so it is a real cost.
It also buys cosmetics and upgrades. According to the wiki, Sin crafts certain robes, upgrades and decorates the Temple, re-indoctrinates followers, and buys the Cowboy and 
Goat fleeces for 10 and 5 Sin.
It even saves you time. The wiki notes you can spend Sin to reset 
Purgatory after a run without waiting an in-game day, and to raise Sin-themed buildings.
Harvest Sin from one follower too often and they become Damned. Per the wiki, when you extract Sin the game checks the last six harvests, and if at least three were from the same follower, that follower is Damned and forced from the cult through a black hole.
One trait softens the odds. According to the wiki, a follower with the Pure of Heart trait has their Damnation chance reduced to 20%, making them safer Sin sources.
The fix is rotation. The wiki recommends keeping at least two Pure of Heart followers, or three ordinary ones, to switch between when farming Sin, and avoiding huge single-follower Sin dumps like the Sinner's Pride ritual.
Rotate your Sin farmers deliberately. In practice a Damned follower flees and must be beaten on a crusade to free them, so spreading Sin extraction across several followers is far cheaper than hunting down the ones you damned.
Sin's tagline sums up the cult. Per the wiki, the resource is captioned "teach them to sin, then sell them salvation," a neat summary of the whole Sins of the Flesh loop.
Traits shift Sin output. According to the wiki, Hedonist and Unrepentant 
followers generate more Sin, while Ascetic and Virtuous ones generate less, so you can build a flock tuned for Sin farming.
Damned followers come back as enemies. The wiki notes a Damned follower is randomly encountered on crusades once all four Bishops are beaten, arriving with the screen tinted red and slow projectile attacks, and defeating them frees them.
Sin sits at the center of the cult's darker economy. These guides cover the DLC it came from, the Temple and fleeces it pays for, and the followers it puts at risk.
Game data and screenshots adapted from cult-of-the-lamb.fandom.com, used under CC BY-SA 3.0. Original content remains the property of the wiki contributors and Massive Monster and Devolver Digital.