The Bible clearly warns that in the end times, a world-wide leader, the antichrist (also mentioned as the "beast" in the Bible) will rise to power. His government will impose people to receive the "mark of the beast" in the right hand or forehead in order to buy and sell.
The Bible strongly warns that whoever takes this mark will spend eternity in hell for identifying with the antichrist and his world system.
"He causes all, both small and great, rich and poor, free and slave, to receive a mark on their right hand or on their foreheads, and that no one may buy or sell except one who has the mark or the name of the beast, or the number of his name. Here is wisdom. Let him who has understanding calculate the number of the beast, for it is the number of a man: his number is 666." Revelation 13:16-18
"Then a third angel followed them, saying with a loud voice, 'If anyone worships the beast and his image, and receives his mark on his forehead or on his hand, he himself shall also drink of the wine of the wrath of GOD, which is poured out full strength into the cup of His indignation. He shall be tormented with fire and brimstone in the presence of the holy angels and in the presence of the Lamb. And the smoke of their torment ascends forever and ever; and they have no rest day or night, who worship the beast and his image, and whoever receives the mark of his name.' "
"Here is the patience of the saints; here are those who keep the commandments of GOD and the faith of JESUS." Revelation 14:9-12