Except the antichrist was probrably the Gnostics, that John was reffering to in 1John as, they believed Jesus was God (which is true) and did not die on the cross as a man as well which is blasphemy.
This is different from the beast and the son of perdition (who is Satan) who come at a later date and set up the abomination of desolation.
Forum:
"Cults," Sects, and "New Religious Movements"