“Reverent” and “quiet” are not synonyms.
But you would never know this from attending Primary. How many times have you heard, “Thank you for being such reverent children!” Guess what? You have no idea if they are being reverent. All you can tell is whether they are quiet. For all you know, they could be thinking about torturing bunnies. Reverence is more than just quietly sitting.
I don’t think this is a semantic quibble. A kid who is quiet but not particularly reverent who is thanked for their so-called ‘reverence’ will develop a very strange idea as to what it means to be reverent.
Please: just thank the kids for being quiet or ask them to be quiet.