Sorry, I still don't buy that was an appropriate forum. Sure, the Dems have no decorum and will gleefully violate norms to slam Trump. But the reason you shouldn't politicize religious events is not out of respect for your political foes, but out of respect for the religious moment itself.
And as for the idea that it is okay to "speak truth" anywhere, that's simply ridiculous. I'm sure all of us can think of plenty examples of "truths" that you should refrain from speaking in places like churches, at weddings, funerals etc..