The New Testament makes it clear that before the final establishment of God’s kingdom, all the forces of evil must do their worst. The “man of sin” (as Paul calls him in 2 Thess. 2:3) is identified with those who deny both God and Christ.
The actual word Antichrist is found only in John’s epistles. There is not just one Antichrist, John says: “As you have heard that the Antichrist’s coming, even now many antichrists have come” (1 John 2:18).
It could, in fact, be anyone: “Many deceivers have gone out into the world who do not confess Jesus Christ as coming in the flesh. This is a deceiver and an antichrist” (2 John 7).
The book of Revelation, with its visions of the final showdown between God and evil, does not use the name Antichrist, but it does speak of the Dragon, the two Beasts, and the False Prophet, all of them opposing and persecuting God’s people.
Throughout history, Christians have pointed out many historical figures (including other Christians) as the Antichrist: various popes, Martin Luther, Napoleon, Hitler, Stalin, Nero, and so forth. We need to recall John’s truth: There are many Antichrists.