1 John 2:18
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 2:22
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 4:3
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.

2 John 1:7
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.

Baha'u'llah cannot be the antichrist because:

The antichrist denies that Jesus Christ is come in the flesh, but Baha'u'llah affirms not only the virgin birth of Jesus but his sinless life and sacrificial crucifixion, all of which occurred in the flesh.

The antichrist denies the Son and the Father, but Baha'u'llah affirms both the Divinity and Sonship of Jesus the Christ and praises Him abundantly. Baha'u'llah also calls all humanity to return to God, and all who become Baha'is grow to love Christ, even if they came from very different backgrounds such as Judaism, Buddhism, Hinduism, Atheism.

The antichrist denies that Jesus is the Christ, but Baha'u'llah affirms that Jesus is the Christ and anyone who becomes a Baha'i must believe in Jesus as the Christ. In the last ten years alone, literally millions of Hindus have come to know and love Jesus Christ through their belief in Baha'u'llah. And many Christians, including myself, say their love for Jesus has grown greatly since they became Baha'is.