Revelation 13:16-17

13:16 He also caused everyone (small and great, rich and poor, free and slave) to obtain a mark on their right hand or on their forehead. 13:17 Thus no one was allowed to buy or sell things unless he bore the mark of the beast – that is, his name or his number.

Revelation 14:9

14:9 A third angel followed the first two, declaring in a loud voice: “If anyone worships the beast and his image, and takes the mark on his forehead or his hand,

Revelation 14:11

14:11 And the smoke from their torture will go up forever and ever, and those who worship the beast and his image will have no rest day or night, along with anyone who receives the mark of his name.”

Revelation 16:2

16:2 So the first angel went and poured out his bowl on the earth. Then ugly and painful sores appeared on the people who had the mark of the beast and who worshiped his image.

Revelation 19:20

19:20 Now the beast was seized, and along with him the false prophet who had performed the signs on his behalf – signs by which he deceived those who had received the mark of the beast and those who worshiped his image. Both of them were thrown alive into the lake of fire burning with sulfur.

Revelation 20:4

20:4 Then I saw thrones and seated on them were those who had been given authority to judge. I also saw the souls of those who had been beheaded because of the testimony about Jesus and because of the word of God. These had not worshiped the beast or his image and had refused to receive his mark on their forehead or hand. They came to life and reigned with Christ for a thousand years.