"Honor the absent," as the saying goes. In other words, don’t be nasty when you’re talking about someone who isn’t there. How many Christians do this? I would suspect most of us. Interestingly, one of the Gospels has Jesus saying that anyone who calls his brother "raca" (an Aramaic word for "fool") will be severely judged, and liable to the "fires of Gehenna."
Scripture scholars say that when an Aramaic word is preserved in the text it’s a sure sign that the Gospel writers are preserving a word that was so unusual that it struck the original listeners in a profound way. In other words, we’re almost 100% sure that we’re hearing the actual word that came from Jesus’s lips; and in this case it has to do with malicious speech. So let’s pay attention to that insight: there are other ways of throwing stones.