A Pillar of the Community

 is a side quest in Fallout 4.

Detailed walkthrough
The cult leader, Brother Thomas, will try to convince the Sole Survivor to join their group. He will make grand statements about improving the lives of everyone in the Commonwealth. If one agrees to go ahead and join the group, Thomas will take the player character into the back room of the amphitheater and ask him to forfeit all of his worldly possessions in favor of the Pillars of the Community.

If one question this, Thomas will reveal his true intentions as a con-man, and threaten the player's life. There is a persuasion option to threaten Thomas, one that will deliver the player character from the situation with all of his possessions while also avoiding a fight. If the player refuses Thomas's proposition, he and all of his followers will immediately become hostile and attack the player character.

If the player character does kill Brother Thomas and his followers, Thomas will respawn later (at least for the Emogene quest) and a persuasion option threatening him will have the Sole Survivor say they "killed the last guy running this scam".