Curiosity, piqued.
Apparently this is nothing new; not only do the Forever 21 bags all carry the reference to the Bible verse:
but there are plenty of other chains that have the same practice. Both here and here are some other examples.
Which makes me wonder, if there's a god, I wonder how he feels about "hamburger and cheeseburger wrappers [pointing] to Revelation 3:20". I hope he'd be pissed off by the pettiness of it.