Revelation 13:11-18

Then I saw another wild beast coming up from the ground. It had two horns like a ram, but it spoke like the dragon. It operated in all the authority of the first beast on its behalf, causing the earth and its inhabitants to worship the first beast, whose mortal wound had been healed. It performed great miracle-signs, even publicly causing fire to fall out of heaven to the earth. And through these startling miracles that he performed on behalf of the first beast, he deceived the world, telling the people to erect a statue in the image of the beast that had been wounded by the sword and yet lived. The beast from the earth was empowered to breathe life into the image of the first beast so that it could speak and kill those who refused to worship its image. It also caused everyone, small and great, rich and poor, free and bound, to be marked on the right hand or on the forehead. This meant no one could buy or sell unless they had the mark; that is, the name of the beast or its number. This will require wisdom to understand: Let the one with insight interpret the number of the wild beast, for it is humanity’s number —666.