convert_family_to_faith_effect

convert_family_to_faith_effect = {
	if = {
		limit = { NOT = { exists = scope:puppet_or_actor } }
		scope:actor = { save_scope_as = puppet_or_actor }
	}
	if = {
		limit = { NOT = { exists = scope:old_faith } }
		scope:recipient.faith = { save_scope_as = old_faith }
	}
	every_in_list = {
		list = spouses_and_family_to_convert
		# Make crypto-religionists of them, if applicable
		if = {
			limit = {
				$FALSE_CONVERSION$ = yes
				faith = scope:recipient.faith
			}
			if = {
				limit = {
					exists = scope:conversion_rite
				}
				convert_to_rite_with_consequences_effect = { RITE = scope:conversion_rite }
			}
			else = {
				convert_to_rite_with_consequences_effect = { RITE = scope:puppet_or_actor.rite }
			}
			make_character_crypto_religionist_effect = { CRYPTO_RELIGION = scope:old_faith }
			# Grab the character's recently added crypto secret
			if = {
				limit = {
					any_secret = { type = secret_crypto_religionist }
					exists = secret_faith
					# Ignore the crypto secret if it's not new
					# This prevents the edge case of family members finding out about other family's different crypto faiths
					secret_faith = scope:old_faith
				}
				random_secret = {
					type = secret_crypto_religionist
					save_scope_as = crypto_religionist_secret
				}
			}
			# Make the secret known to all other family members
			every_in_list = {
				list = spouses_and_family_to_convert
				if = {
					limit = {
						exists = scope:crypto_religionist_secret
						prev != this
					}
					scope:crypto_religionist_secret = {
						reveal_to_without_events_effect = { CHARACTER = prev }
					}
				}
			}
		}
		else = {
			if = {
				limit = {
					exists = scope:conversion_rite
				}
				convert_to_rite_with_consequences_effect = { RITE = scope:conversion_rite }
			}
			else = {
				convert_to_rite_with_consequences_effect = { RITE = scope:puppet_or_actor.rite }
			}
		}
		if = {
			limit = {
				$FORCED$ = yes
			}
			hidden_effect = {
				add_character_flag = {
					flag = converted_by_forced_conversion_interaction
					years = 5
				}
			}
		}
	}

	scope:recipient = {
		bastard_to_wild_oat_conversion_interaction_effect = yes
	}

	# Struggle Catalysts.
	if = {
		limit = {
			scope:recipient = { is_important_or_vip_struggle_character = yes }
			scope:puppet_or_actor = {
				any_character_struggle = {
					involvement = involved
					activate_struggle_catalyst_secondary_character_involvement_involved_trigger = {
						CATALYST = catalyst_demanding_important_conversion
						CHAR = scope:recipient
					}
				}
			}
		}
		scope:puppet_or_actor = {
			every_character_struggle = {
				involvement = involved
				limit = {
					activate_struggle_catalyst_secondary_character_involvement_involved_trigger = {
						CATALYST = catalyst_demanding_important_conversion
						CHAR = scope:recipient
					}
				}
				activate_struggle_catalyst = {
					catalyst = catalyst_demanding_important_conversion
					character = scope:puppet_or_actor
				}
			}
		}
	}
}

As written in game/common/scripted_effects/00_religious_interaction_effects.txt.