In a broader context what this means is the privatization (or, if you will, the domestication) of religion. There is an underlying, unspoken (perhaps unconscious) assumption: Religion is okay if engaged in by consenting adults in private, not so if it spills over into public space. The similarity with pornography is telling: It comes through the mail in plain brown envelopes; you are free to view the contents in the privacy of your home; just don’t view them in a public place.

…Of course the most coercive efforts to privatize religion (if you will, tolerating it if at all in a plain brown envelope) were made in Communist Russia and China. (For a masterly comparison of the two cases see Christopher Marsh, Religion and State in Russia and China, 2011.) The two outcomes have been very different, until now pretty much opposite. During the Cultural Revolution under Mao all religions were bloodily suppressed. Since then, it seems to me that the religion policy of the regime has veered away from Marxist atheism to what I perceive as a sort of Confucian damage control—religion is basically an illusion, but potentially dangerous.

—Peter Berger, “Religion In A Plain Brown Envelope”