207. Informers
Teshuvah 3:11
One who separates himself from the community is among those without a share in the Next World even though he has committed no sins per se. If a person separates himself from the rest of Jewry and does not fulfill mitzvos with them, does not share their troubles, and does not join their fasts, but instead follows his own path as if he were a member of another nation, he does not have a share in the Next World.
One who haughtily commits sins in public as Yehoyakim did - whether they be small sins or major ones - has no share in the Next World. This is considered acting brazen against the Torah because he openly defied the Torah without feeling any shame.
Teshuvah 3:12
There are two types of those who betray their fellow Jews to the non-Jewish authorities: one who betrays his fellow so that the authorities may kill or beat him, and one who hands over another’s money or property. Neither of these has a share in the Next World.