The term pagan is from the Latin paganus, an adjective originally meaning “rural”, “rustic” or “of the country.” As a noun, paganus was used to mean “country dweller, villager, and contrasted with the religion in favor in the imperial court.
In that sense, Christianity is now a pagan religion. Christianity is, to my way of thinking, not in favor in our government. It is in favor in ‘flyover country’ which would be rural, rustic places, or in small villages.
Some (Muslims and Jews, and perhaps the occasional Roman Pagan) see the doctrine of the Trinity as approaching polytheism.
The Buddha said “The things of G-d are unknown, and unknowable, so why argue?”
In no dictionary definition does "pagan" apply to Christianity -- indeed, the dictionary tells us the word was first used in the 14th Century, meaning it was coined by educated Christians to describe rural heathens.
So, if you wish to tell us that Christianity today is stronger amongst independent rural folks than among our more educated urban elites, then just say that.
Don't be calling people "pagans" when all you really mean is rural.
And don't be insulting us rural folks, pal.