Here's a very good short essay from the NY Times by philosopher Justin McBrayer entitled "Why Our Children Don’t Think There Are Moral Facts". It discusses some common mistaken uses of the words 'facts' and 'beliefs' or 'opinions.' I have had some lines on a logic handout that I've used many years that addresses this same issue:
The final lines from McBrayer's article sum it up nicely:
Our children deserve a consistent intellectual foundation. Facts are things that are true. Opinions are things we believe. Some of our beliefs are true. Others are not. Some of our beliefs are backed by evidence. Others are not. Value claims are like any other claims: either true or false, evidenced or not. The hard work lies not in recognizing that at least some moral claims are true but in carefully thinking through our evidence for which of the many competing moral claims is correct. That’s a hard thing to do. But we can’t sidestep the responsibilities that come with being human just because it’s hard.
That would be wrong.