Popular fiction and some preachers would have you believe that the Antichrist is a child born of the devil to be equivalent to Jesus in the final war. This comes from the belief that the devil is somehow the equal and opposite of the Father and Jesus. The Bible states that Jesus is equal to the Father but that Lucifer was merely an angel tossed out Heaven before anyone was born. I've been taught that the devil is forever locked in spiritual form and unable to gain a body. He has power only through us. Thus he cannot father a child and that child would be nowhere near the equal of Jesus.
What defines Christ, the Saviour, is compassion. He was willing to forgive the repentant, condemning only the money-changers exploiting the faithful, the hypocritical religious leaders, and child abusers. He commanded those who would call themselves Christians to leave judgment and the saving of souls to him. We are to work on our own salvation not that of others. We are to present the message and move on if it is not accepted, not to condemn or convert. We are to love everyone. Only one who has lived perfectly, suffered the pain of all, and sacrificed himself for our good is qualified to judge. The rest of us have beams blocking our view.
Like matter and antimatter, there are many Christians and many Antichrists.
As Christians we take his name upon us and are to act as he would. This means that we can be Christians, hypocrites, or Antichrists. A Christian works on building the kingdom of compassion. A hypocrite claims righteousness while ignoring their failings to point out those in others. An Antichrist claims righteousness while actively working against the kingdom by judging and trying to covert others through force. They sow division and antipathy rather than compassion. They preach violence and greed in the name of Jesus. They are the false prophets of fundamentalism who ignore the true fundamentals of compassion.
The Father sent one saviour. Only one saviour will come again. The claim by some Antichrists that any other leader is chosen by god save the people is a dead giveaway of what they are. No one else is the Christ.
A Christian is commanded to build the kingdom of compassion here and now, not wait for a miraculous escape before the world is burned and rebuilt. An Antichrist is selfish enough to expect the rescue and not care what happens to everyone else. Selfishness and compassion. Selfishness is the root of all evil. Compassion is the root of all good.
If you are not building then you are tearing down.