1 John 4:2-3 By this you know the Spirit of God: Every spirit that confesses that Jesus Christ has come in the flesh is of God, and every spirit that does not confess that Jesus Christ has come in the flesh is not of God. And this is the spirit of the Antichrist, which you have heard was coming, and is now already in the world.
Civilization continues to erode as the world is being prepared for its greatest deception, the appearance of the false messiah -- the Antichrist. The word literally means "one against Christ" and also, one "in place of Christ." Yeshua (Jesus) predicted and warned his disciples and all believers of this dangerous development in the last days.
Toward the end of the first century, the gospel message came under the influence of Greek philosophy and culture, and was corrupted by Greek "Gnosticism" to the point of heresy. "Gnosis" - meaning "knowledge", in this case, special, particular, hidden, esoteric, "spiritually enlightened" knowledge, was the basis and goal of Gnosticism, both at that time, and today in its many contemporary expressions. These spiritual adepts claimed to be the "spiritually enlightened" ones, some of whom inserted themselves among the true believers to draw followers and to replace the true revelation of Yeshua (Jesus) with a counterfeit.
The apostles addressed this heresy in numerous letters. Paul exhorted Timothy to, "Turn away from godless chatter and the opposing ideas of what is falsely called knowledge (gnosis)." [1 Timothy 6:20]
Most of these Gnostics believed Yeshua, whom they called, "Christ", to be divine, but that he was only one of the "aeons" or "divine spiritual beings." They taught that Christ only seemed to be human, that he was never actually born to a Jewish household, growing up in Nazareth, and that He was never actually crucified nor bodily risen from the dead. This Gnostic "Christ" revealed himself only to reaffirm and exemplify the message of "spiritual enlightenment" for those who sought this "special revelation."
And they believed that he was only one of numerous "prophets" appearing from time to time with this "universal" Gnostic message. The apostle John was well aware of this and was led by the Holy Spirit to teach and warn of it.
And Gnosticism is alive and well today. One of its ubiquitous signs is the "all seeing eye", which is traceable to ancient Egypt as the "eye of Horus" and is associated with the same "special revelation" or "enlightenment" propounded by the Greek Gnostics. The same false rendering of Yeshua also abounds today in various Gnostic teachings, so that the words of John the apostle are just as relevant as ever, perhaps even more so. According to Gnostic teachings, Jesus is no longer the savior of the world who died for sins and rose from the grave, but a spiritual adept who appeared to exemplify and teach the transcendent knowledge of "enlightenment."
There is a dark being in the scriptures who is associated with "light" [2 Corinthians 11:14] and who is behind all false teachings of "enlightenment." His light is darkness. [Matthew 6:23]. So our brother John carefully warns us to, "Test the spirits ... to see whether they are from God." The test is simple but unequivocal. "Every spirit that confesses that Jesus Christ has come in the flesh is of God." "In the flesh!"; not a "spiritual, angelic, aeon/avatar, one of many bringing a false message and a false "light"... but a unique incarnation of the Creator YHVH, who lived a human life, and died a human death, and was physically, bodily raised to eternal life.
The true Gospel message is simple and beautiful, and accessible to all. It is not a deep esoteric knowledge, or mystical experience. We can rejoice in the beautiful and simple fact that in Him, namely "Yeshua (Jesus),... are hidden all the treasures of wisdom and knowledge." [Colossians 2:3]