1John 2:18? Do Christians realize there are many Antichrists and they began appearing in the 1st Century CE?

John is talking about the last days, the time between Christ's first and second coming. The first century readers of 1 John lived in the last days, and so do we. During this time, antichrists (false teachers who pretend to be Christians and who lure weak members away from Christ) will appear. Finally just before the world ends, one great antichrist will arise (Revelation 13; 19:20; 20:10) We do not need to fear these evil people, however. The Holy Spirit shows us their errors, so we will not be deceived. However we must teach God's Word clearly and carefully to the peripheral, weak members among us so that they won't fall prey to these teachers who "come to you sheep's clothing, but inwardly are ravenous wolves' (Matthew 7:15).