mark of the beast

noun

1. (in the Bible) a physical mark placed on those who worship the Antichrist and are in opposition to God.
2. something taken to be a sign of evil, corruption, or infamy:

   The way he talks about the uselessness of politics, you'd think that voting in a national election was the mark of the beast.

Word History and Origins

Origin of mark of the beast¹

First recorded in 1350–1400; Middle English