1 John 2:18-25 (ESV)
Children, it is the last hour, and as you have heard that antichrist is coming, so now many antichrists have come. Therefore we know that it is the last hour.  They went out from us, but they were not of us; for if they had been of us, they would have continued with us. But they went out, that it might become plain that they all are not of us.  But you have been anointed by the Holy One, and you all have knowledge.  I write to you, not because you do not know the truth, but because you know it, and because no lie is of the truth.  Who is the liar but he who denies that Jesus is the Christ? This is the antichrist, he who denies the Father and the Son.  No one who denies the Son has the Father. Whoever confesses the Son has the Father also.  Let what you heard from the beginning abide in you. If what you heard from the beginning abides in you, then you too will abide in the Son and in the Father.  And this is the promise that he made to us— eternal life.
“Therefore we know that it is the last hour.” And thus John denounces the most popular lie not of the truth in the 20th and now the 21st century, a lie shared by many Baptists, Evangelicals, Pentecostals, Jehova Witnesses, Mormons, and the list goes on. It is that of Millennialism, or Chiliasm as they called it in the Reformation, Jewish Myths as they called it in Paul’s day (Titus 1:14). Those myths caused a great many contemporary compatriots to completely miss the messiah they were waiting for, because he didn’t usher in the earthly kingdom they were expecting, but rather told Pilate, my kingdom is not of this world.
This lie rests on the idea that when John wrote it was not the last hour, but that that hour is still yet to come. It is an absolutely seditious lie that continues to undermine the gospel and the authority of the Apostles of Christ. It picks and chooses its way through scripture forcing a completely foreign idea of salvation upon scripture. In the end it is incompatible with the gospel, and replaces it as a pseudo gospel. Perhaps most often it just becomes a distraction, which is why Paul merely comments to avoid the myths. But it can lead to a fearful and harsh life.
John knew that the last hour had come. Anti-christs had gone into the world. For some reason people are always trying to find “The anti-Christ.” I think whoever happens to be sitting in the “throne of Peter” today fits the bill. But that doesn’t mean the man with the funny hat is the only anti-Christ to be worried about, I have a perfectly diabolical one much closer to home here.
There should be a word on anti-Christ. People take this to mean someone who openly opposes Christ. But that really isn’t the picture. An anti-christ is usually much more deceptive than that. They use the word Christ, they talk about Jesus, they promote morals and generally a good life. He then subtly deceives them into putting their trust in someone other than Christ, something like their works, or temple recommend. They may even say that Jesus is the Christ, but then change the meaning of what it means to be the Christ.
But Christ made a promise to us, and in that promise we trust. That promise is Eternal life.