Is there a word for a person or action where they no longer believe in something?
I am not looking for "apostate". Rather, I am looking for the word (verb/noun) which means that someone no longer thinks along those lines as they did before. In short, they gave up their old ideas.
‘To recant (on ones position)’ might fit what you’re looking for.
If it’s more religious in context then ‘to lose (ones) faith/belief’ is a good fit.