There are a handful of groups with systems of merit where you climb a social ladder/ranking hierarchy.

At a very high level, members will be invited to a retreat where they are given the option to commit a terrible crime. Usually this crime is a murder.

Those who choose to murder are given a "promotion". But what they don't know is that those who choose not to murder are given a similar "promotion".

Both of these two people will serve more or less together, and because of structural builtins, they don't discuss these rituals or promotions ever.

At the highest level, those who chose to commit the crime are the only ones who can achieve the highest ranks -

all the while, those who chose not to commit the crime are led to believe that was the only acceptable choice for the "organization".

It is not, and those people are just used for other things. Sometimes they are eliminated.

In the case that a person was to be murdered as the act of indoctrination; that person is always killed anyway.