Hymn of One

Bree's religion has never been directly stated in the series, although many believe her to be a member of a Thelemic religion of some sort or Argenteum Astrum, as a picture of Aleister Crowley is prominently featured in her bedroom. Moreover, the word Thelema is written in Greek (Θέλημα) at the bottom of the page at lonelygirl15.com.

Bree spent a long time preparing to undergo a ritual ceremony related to her religion. In The Ceremony Is Tomorrow :) Bree tells us that the ceremony will take place on October 12, 2006 which is also Aleister Crowley's birthday.

In Daniel, Be Careful... Bree talks about the importance of the secret nature of her religion. Aleister Crowley also talks about secrecy.

In I'm Hiding Out, Daniel described Bree's religion as a cult.