Just to add an answer to Cecil's, which is solid, but to elaborate more closely on the ideal of a personal antichrist.
Anti in the context of Christ refers to not only being opposite or opposed to, but also "in place of." Since, from Revelation, we see that this antichrist is given power and authority by the dragon (universally recognized as Satan), the antichrist is indeed a singular person -- but beyond that, he is meant to REPLACE the real true Christ, Jesus.
Just look at some parallels, again from Rev 13 as Cecil used:
3 And I saw one of his heads as if it had been mortally wounded, and his deadly wound was healed. And all the world marveled and
followed the beast. 4 So they worshiped the dragon who gave authority
to the beast; and they worshiped the beast, saying, “Who is like the
beast? Who is able to make war with him?”
Two things here -- first we see the "beast" (the one empowered by the dragon, satan, has been mortally wounded but was healed). As a result this causes people to marvel and worship satan. This is a simulation of Jesus Christ's resurrection from the Cross.
The one goal of this is satan is prideful and wants to be in the place of God. Naturally his antichrist would stand to be in place of Jesus. We see this beginning in the Old Testament, for example, Isaiah 14:
12 “How you are fallen from heaven, O Lucifer,[b] son of the morning!
How you are cut down to the ground, You who weakened the nations! 13
For you have said in your heart: ‘I will ascend into heaven, I will
exalt my throne above the stars of God; I will also sit on the mount
of the congregation On the farthest sides of the north; 14 I will
ascend above the heights of the clouds, I will be like the Most High.’
Let's go back to Christ in the wilderness where satan tries to tempt Jesus. From Matthew 4:
8 Again, the devil took Him up on an exceedingly high mountain, and
showed Him all the kingdoms of the world and their glory. 9 And he
said to Him, “All these things I will give You if You will fall down
and worship me.”
Satan wants worship, that's his only price for all the nations of the world. This is what got him thrown down from heaven, to the earth, where he has power and authority over this world until Christ's return; and this is his motivation for an antichrist. Christ warns us in Matthew 24 to be weary of false Christs and false prophets whom perform wonders. The dragon, the beast he raises up (the antichrist) and the antichrist's prophet itself imitates the Holy Trinity.
Again, to imitate, and be in place of, the true Godhead. Since Jesus Christ is our personal Lord and Savior, it only makes sense the knock off attempt to take his place for non-believers would be a personal savior-like figure as well.