I agree with your post, NL.
I have been away for a while, because I found the tone of exchanges here were not fulfilling very well the Pauline admonition: “Whatsoever things are good, whatsoever things are true , whatsoever things are of good report, think on these things”.
The definition of sarcasm is “to use irony to mock or convey contempt”.
I think sarcasm-—according to that definition-— doesn’t fit well in Christian dialogue.
I also agree with you that we have an obligation to bring light out of darkness, for St. John reminds us that we are children of the light.
Reading postings here, I’m aware that there are non-Catholics who have a deep and lively faith and I am bound in Christ-like behavior to honor that and to rejoice in it. I tend to believe that the Lord Jesus would rather we seek and find what goodness is manifest in one another. That would be a far better way-—”a more excellent way” as St. Paul would say-—of being disciples and witnesses of Christ.
The definition of sarcasm is the opposite, since it is intended to mock, show contempt, or as in another definition, “to cause pain”.
Peace be with you also.