What is the Antichrist according to modern day Christianity?
The Antichrist is the end-times false messiah who seeks, and achieves, world domination during the tribulation so that he can destroy Israel and all followers of Jesus the Christ.
“Little children, it is the last time: and as ye have heard that antichrist shall come, even now are there many antichrists; whereby we know that it is the last time”. 1 John 2:18
The specific term antichrist is used seven times in Scripture, twice here in 1 John 2:18 and also in 1 John 2:22; 4:3; and twice 2 John 7.
The meaning of the term antichrist is simply “against Christ.” As the apostle John records in First and Second John, an antichrist denies the Father and the Son (“Who is a liar but he that denieth that Jesus is the Christ? He is antichrist, that denieth the Father and the Son”. 1 John 2:22), does not acknowledge Jesus (“And every spirit that confesseth not that Jesus Christ is come in the flesh is not of God: and this is that spirit of antichrist, whereof ye have heard that it should come; and even now already is it in the world”. 1 John 4:3), and denies that Jesus came in the flesh (“For many deceivers are entered into the world, who confess not that Jesus Christ is come in the flesh. This is a deceiver and an antichrist”. 2 John 1:7). There have been many “antichrists,” as 1 John 2:18 states. But there is also coming the Antichrist.
Most Bible prophecy/eschatology states the Antichrist will be the ultimate embodiment of what it means to be against Christ. In the end times/last hour, a man will arise to oppose Christ and His followers more than anyone else in history. Claiming to be the true Messiah, the Antichrist will seek world domination and will attempt to destroy all followers of Jesus the Christ and the nation of Israel.
Other biblical references to the Antichrist include..
“And he shall speak great words against the most High, and shall wear out the saints of the most High, and think to change times and laws: and they shall be given into his hand until a time and times and the dividing of time”. Daniel 7:25
The leader who establishes a 7-year covenant with Israel and then breaks it in Daniel 9.
The king who sets up the abomination of desolation. “But when ye shall see the abomination of desolation, spoken of by Daniel the prophet, standing where it ought not, (let him that readeth understand,) then let them that be in Judaea flee to the mountains”: Mark 13:14 (cf. Daniel 9:27).
The man of lawlessness in 2 Thessalonians 2:1–12.
The rider on a white horse (representing his claim to be a man of peace). “And I saw, and behold a white horse: and he that sat on him had a bow; and a crown was given unto him: and he went forth conquering, and to conquer”. Revelation 6:2
The first beast—the one from the sea—in Revelation 13. This beast receives power from the dragon (Satan) and speaks “proud words and blasphemies” (verse 5) and wages war against the saints (verse 7).
The Antichrist/beast, along with his false prophet, will be thrown into the lake of fire alive, where they will spend all eternity in torment. “And the beast was taken, and with him the false prophet that wrought 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”. Revelation 19:20
“And the devil that deceived them was cast into the lake of fire and brimstone, where the beast and the false prophet are, and shall be tormented day and night for ever and ever”. Revelation 20:10