None. They have a word for people like that.
Apostate.
If you had lived in the time when religion still ruled public life, that word would fill you with dread. Apostasy was a capital crime. It could and did get people killed.
But ordinary run-of-the-mill questioning of faith did not an apostate make. Apostasy was formal renunciation of the faith. If you just fell away from God, that’s a private matter between you and God, and you’ll be judged by Him in the afterlife.
But if you not only fell away from the faith, but then started proselytising a different faith, then you’re calling down the full wrath of the Catholic Church.
But that’s the past, why do I say that it still doesn’t happen today?
Belief is something you have to choose before you can really understand it. You have to choose it, and you have to keep choosing it. Once you understand God, that understanding never goes away. Belief comes before understanding. Once you understand, then belief isn't necessary. You know.
Nothing about this has changed, it’s always been this way. Belief used to be compelled, but that only ever got you part of the way to true understanding. If you wanted more from your belief and more from your faith, you had to earn it.
This is what made apostasy such an awful crime. You entered into the kingdom of God, sampled the many delights inside, then decided you wanted it all for yourself. You’re no better than Lucifer.
The rest of the flock, who don’t want or need the glory of true belief, can be saved in that they have learned right ways of thinking and being and conducting themselves in society, contributing to the common good.
But to really understand the sheer immensity of God, what He is and what He does, that’s a lesson that can never be unlearned. It’s bigger than a religion, bigger than a church, bigger than you, bigger than your belief in it.