If you have strong opinions on something controversial and you express them on Facebook, you cannot expect others to not challenge them. Venting on social media? That’s certainly your choice. But if you really don’t want dissenting views and aren’t interested in having a discussion with someone with a different opinion, go get all worked up to your echo chamber instead.
Do you want to potentially change someone’s mind (or at least get him/ her to consider something in a new way)? Or do you simply want validation from your likeminded friends?
If your take on an issue can’t stand cross-examination, maybe it’s time for you to reconsider it. If you yourself cannot tolerate respectful debate and disagreement, perhaps tone down the passion a bit.