Yeah, that is absolutely a huge part of it. The reinforcement from their "community" is an essential part of how people are radicalized.
(To cite that claim, here is my write-up on the subject with valid citations. My blog has ads turned off and I don't benefit from it in any way.)
The rationalizing comes in when their beliefs are challenged by other people/other media (or reality checks when QAnan predictions repeatedly fail to come to fruition).