I generally like to back up my beliefs with facts, data, observation, etc. Am I required to, no. Will I attempt to back up my opinions if called upon - yes. I do like to see the facts first or confirm my beliefs, opinions, etc do have a sound factual basis. Unfounded beliefs like the "stolen election" led to riots at the Capitol rather than a peaceful transfer of power. Unfounded beliefs like the legal system is systemically racist also led to rioting. As a matter of fact, I'd say a lot if not most of the division in this country is due to unfounded beliefs. As I've said before, if there really was evidence of a stolen election, I would have been at the Capitol kicking down the doors. If the legal system was really systemically racist, I would have been in the street rioting. So yes, proof is important to me.
That said other things do fall outside the realm of "factual" - ie does life begin at conception?