'Anti christ' in the Bible

Dear children, it is [now] the last hour [i.e., the final period of God's dealing with people on earth], and since you have heard that an antichrist [i.e., a person who is against Christ] is coming, even now [you should be aware that] many antichrists have [already] come. This is [one way] we know that this is the last hour.

Who is the liar? It is the person who denies that Jesus [truly] is the Christ [i.e., God's specially chosen One]. This person is the antichrist [See verse 18]; he is the one who denies [the truth about] the Father and the Son.

But every spirit who does not proclaim [this truth about] Jesus is not [speaking] from God. And this [person] represents the spirit of the antichrist [See 2:18-22; II John 7], whom you have heard would come. Well, now he is already here!