Wake the Living Dead

Jesus has John write a letter to the Church of Sardis, which, while it has a reputation with the world, is nearly dead inside save a few whom He threatens to steal away like a thief if they do not watch and repent. And if He does this, they are in such a sinful stupor they won't even notice He took His Spirit and His true Christians out of that Visible Church; but they will at that point be a synagogue of Satan.