"For many deceivers have gone out into the world, those who do not acknowledge Jesus Christ as coming in the flesh. This is the deceiver and the antichrist. Watch yourselves, that you do not lose what we have accomplished, but that you may receive a full reward." (2 John 7-8)For John, the antichrist was not some end-time figure, nor a single person, but a spirit that indwelt many why would come and oppose the teachings and work of Christ. John describes that, in his day, many, not a few, antichrists had already appeared; those who sought to undue the teachings and commands of the Apostles as they followed and taught the things Jesus had taught and commanded them. That many anitchrists should have appeared should not have surprised us. For even Jesus said, "See to it that no one misleads you. Many will come in My name, saying, 'I am He!' and will mislead many." (Mark 13:5-6) Furthermore, Jesus also warned us saying, "So if they say to you, 'Behold, He is in the wilderness,' do not go out, or, 'Behold, He is in the inner rooms,' do not believe them." (Matthew 24:26)
Just as in John's day, we should not be surprised to find many antichrists alive and well in our world today. John writes that we should guard ourselves against them and not succumb to their deception. John understood that the Christian life is not about starting well but finishing well. Many start out with great joy and appear as brilliant starts as they sprint ahead of the rest of us only later to burn out and fall away back into the darkness. The Christian walk is not a sprint but a long-distance endurance race where we must be continually strengthened on the truth and teachings of Christ. Many may come offering shortcuts or easier paths to what we wish for our lives but it is the life of the Spirit that produces true fruit in our lives; true fruit that remains. John's hope is that we would continue steady until the end; building upon what we learned and growing in strength from victory to victory till one day we stand before our King and are invited into eternal dwellings with Him in heaven. That having started well we would finish well. Paul put it this way, "Are you so foolish? Having begun by the Spirit, are you now being perfected by the flesh?" (Galatians 3:3) On the contrary, we should start in the Spirit and end in the Spirit.
One of the key ways to identify these antichrists is to recognize them as deceivers. The Greek word for deceiver means a wanderer or roamer; one who wonders about with no true direction or purpose. You can identify an antichrist by the serpentine path they take in wandering away from the truth. The truth of God is a straight line that starts with God and runs through Adam, Abraham, David, Jesus, the Apostles, the church, us, and then finally ends back with God (with many interleaving connection points omitted for brevity sake). Those who seek to lead you in a path that deviates from this history, seek to lead you away from the truth. We should be wary of those who bring some new doctrine or revelation that has not appeared previously in God's revealed history of redemption. We should reject those who bring a teaching that counters or descents from that of Jesus and His apostles. Anything or anyone who would seek to lead us astray from the historical truth and teaching of God, His prophets, and His apostles is fulfilling the office of antichrist. Let them follow their own crooked path while we follow the straight path of Christ. "I will make them walk by streams of waters, on a straight path in which they will not stumble; for I am a father to Israel." (Jeremiah 31:9)