"just expressing an opinion belief" [Rant]

We tend to value the fact that people have opinions and beliefs, but not how well thought out or constructed they are (perhaps due to the rise of social media and the ubiquity of simple tools to publish content).

I'll give an example. Recently, with respect to the same-sex marriage controversy, someone commented on a facebook post,

"just expressing an opinion",

in response to

"I'm interested in hearing why you think that...",

about their stance on the issue. Opinions are important. However, in this case opinion was confused with belief. It's important that people think. I love to hear a well thought out belief that conflicts with my own. It makes me evaluate merit and do one of three things: reject the stance due to weakness, change my position completely because of the strength of the argument, or modify my belief based on thoughts I hadn't considered before.

I respect having strong beliefs on the nature and existence of truth, but you should be able to defend them in at least a basic sense. It's difficult to value belief that hasn't been thought through. If your beliefs are based on the Bible, be able to give a reason as to why it's authoritative, and why your interpretation of it supports a belief you espouse. Credence isn't dispensed for free; "always [be] prepared to make a defense to anyone who asks you for a reason for the hope that is in you; yet do it with gentleness and respect" (1 Peter 3:15).

Just "expressing an opinion" in the guise of sharing a belief is weak, and I don't want to hear it.