Who is the anti-Christ?
Firstly the anti-Christ is not just singular but many and it is scattered in the World. It is an Opposite to the Truth of God, an Opposite to Jesus the Messenger of the Truth, His true servants and to the Laws and commands of God.
The Bible tells of the identify of the anti-Christ being a spirit against the Truth. This Spirit can exists in Man.
1JN 2:18 Dear children, this is the last hour; and as you have heard that the antichrist is coming, even now many antichrists have come. This is how we know it is the last hour. 19 They went out from us, but they did not really belong to us. For if they had belonged to us, they would have remained with us; but their going showed that none of them belonged to us.
1JN 2:22 Who is the liar? It is the man who denies that Jesus is the Christ. Such a man is the antichrist--he denies the Father and the Son. 23 No one who denies the Son has the Father; whoever acknowledges the Son has the Father also.
1JN 4:1 Dear friends, do not believe every spirit, but test the spirits to see whether they are from God, because many false prophets have gone out into the world. 2 This is how you can recognize the Spirit of God: Every spirit that acknowledges that Jesus Christ has come in the flesh is from God, 3 but every spirit that does not acknowledge Jesus is not from God. This is the spirit of the antichrist, which you have heard is coming and even now is already in the world.
2JN 1:7 Many deceivers, who do not acknowledge Jesus Christ as coming in the flesh, have gone out into the world. Any such person is the deceiver and the antichrist.