“Antichrist” is shown as appearing before the second coming of Christ. But there’s more to the story and the term “antichrist” than just one man.
The meaning of the term antichrist encompasses more than just the end time. It literally means “against Christ” and is variously defined as “adversary of Christ” or “opponent of Christ,” and as a designation for a specific individual who rises on the world scene to defy Christ and His work. In fact, such an enemy will arise, but there have been and are many antichrists who oppose Jesus and His message (1 John 2:18 1 John 2:18Little children, it is the last time: and as you have heard that antichrist shall come, even now are there many antichrists; whereby we know that it is the last time.
American King James Version×).
The Greek-English Lexicon of the New Testament Based on Semantic Domains by Louw and Nida offers a more comprehensive definition: “The term . . . appears to have become increasingly equivalent to a proper name as the personification of all that was opposed to and contrary to the role and ministry of Christ.”
According to the apostle John’s writing, there is a spirit of antichrist, which is a spirit of opposition to the identity and nature of Christ and His ongoing work in His people. Specifically, John was writing to warn of the heresy that denied Christ’s coming in the flesh (1 John 4:3 1 John 4:3And every spirit that confesses not that Jesus Christ is come in the flesh is not of God: and this is that spirit of antichrist, whereof you have heard that it should come; and even now already is it in the world.
American King James Version×; 2 John 6-7). To deny such central biblical truth is to be against Christ and His message.
Like a lamb but speaking as a dragon
In 2 Thessalonians 2, Paul prophesied of a “man of sin,” a liar and deceiver supernaturally empowered by Satan the devil to confuse people in the end time.
Christ inspired John to write of a “false prophet” to come at the end time (Revelation 13:11-18 Revelation 13:11-18  And I beheld another beast coming up out of the earth; and he had two horns like a lamb, and he spoke as a dragon.
 And he excercises all the power of the first beast before him, and causes the earth and them which dwell therein to worship the first beast, whose deadly wound was healed.
 And he does great wonders, so that he makes fire come down from heaven on the earth in the sight of men,
 And deceives them that dwell on the earth by the means of those miracles which he had power to do in the sight of the beast; saying to them that dwell on the earth, that they should make an image to the beast, which had the wound by a sword, and did live.
 And he had power to give life to the image of the beast, that the image of the beast should both speak, and cause that as many as would not worship the image of the beast should be killed.
 And he causes all, both small and great, rich and poor, free and bond, to receive a mark in their right hand, or in their foreheads:
 And that no man might buy or sell, save he that had the mark, or the name of the beast, or the number of his name.
 Here is wisdom. Let him that has understanding count the number of the beast: for it is the number of a man; and his number is Six hundred three score and six.
American King James Version×; Revelation 16:13 Revelation 16:13And I saw three unclean spirits like frogs come out of the mouth of the dragon, and out of the mouth of the beast, and out of the mouth of the false prophet.
American King James Version×; Revelation 19:20 Revelation 19:20And the beast was taken, and with him the false prophet that worked miracles before him, with which he deceived them that had received the mark of the beast, and them that worshipped his image. These both were cast alive into a lake of fire burning with brimstone.
American King James Version×). The prophecy describes a great religious leader: “He had two horns like a lamb and spoke like a dragon” (Revelation 13:11 Revelation 13:11And I beheld another beast coming up out of the earth; and he had two horns like a lamb, and he spoke as a dragon.
American King James Version×). That is to say, he takes on the semblance of (or imitates) Jesus Christ (the Lamb of God) but is empowered by Satan (see Revelation 12:9 Revelation 12:9And the great dragon was cast out, that old serpent, called the Devil, and Satan, which deceives the whole world: he was cast out into the earth, and his angels were cast out with him.
American King James Version×). Historically, a counterfeit version of Christianity fulfills what is described in the prophecies of Revelation.