Sarcasm is very hard to decipher online. A response could be "I don't understand"...or just give yourself time to get the joke. Read back to what you wrote. Maybe it was in response to something earlier you said. Maybe it was in response to previous discussions in other threads. Or maybe it might not make sense.
Some suggestions of sarcasm may include a "LOL" by other members of the forum, especially if they are Greek and they haven't taken offense. Some suggestions of confusion might be silence or just not responding at all to that post. Anger at a comment would be obvious. Either way, prudent to wait and see or as I might say sometimes, "I'm really sorry. I'm bad at inside jokes. I don't understand this."
I think in the context of this, it seems he's not taking it literally, but simply ridiculing at how traditionalists will accuse those who did not wear head coverings as "Godless Greeks", in addition to the "feminist" comment made by the previous poster.
Side effects of sarcasm include squinting at the screen of your computer too long, splitting headache, repercussions of bad jokes, inappropriate thoughts, pulling hair, grinding teeth, pulling teeth (a rare side effect), dry mouth (for yelling too much), sore throat (for yelling too much), rolling over in your future grave, and falling off your chair laughing your gluteal muscles off.
Call your forum doctor today!