apostasy

许多人认为他改变信仰是对宗教的彻底背叛。

Many considered his change of faith to be complete ___apostasy.

她曾是坚定的党员，但后来公开宣布脱离该党。

She was a staunch party member but later publicly announced her ___apostasy from it.

她公开宣布放弃信仰的行为被社区视为严重的叛教。

Her public declaration of abandoning faith was seen as serious ___apostasy by the community.