To give up or renounce one's position or belief.
(intransitive) To commit apostasy.
To renounce totally a religious belief once professed; to forsake one's church, the faith or principles once held, or the party to which one has previously adhered.
‘He apostatized from his old faith in facts, took to believing in emblances.’;
abandon one's beliefs or allegiances
renounce a religious or political belief or principle
‘the property of wealthy Christians was liable to confiscation unless they apostatized’;