The word "Gnosticism" is derived from the Greek word gnosis, which means "knowledge." A lot of contemporary controversy surrounds this word, so it is important to lay some groundwork.
First of all, Gnosticism was not an early Christian "movement," later declared to be heretical. There were many non-Christian Gnostics. And there was no "movement" because Gnosticism was an amorphous philosophy, drifting through many systems of thought. It was not a particular theology taught by a particular person. It was not systematized at all, but rather a way of understanding the world that arose from Greek, pagan, and philosophical schools, interpreted in many different ways.
Gnosticism is an attempt to explain the nature of evil and the manner of salvation from it. There are so many different interpretations that what follows is only a rough guideline.
According to Gnostics, matter is at best unreal, and at worst, evil. Humans are really spiritual entities that have been trapped or imprisoned in a body. In the beginning, the Supreme Creator made a spiritual family consisting of (according to one system) 365 beings called "eons." One of these eons fell into sin. (One system of thought says that Wisdom, a spiritual eon, tried her hand at creation. Her "abortion" turned out to be the material world. According to this way of thinking, the world is an abortion of the spirit, not a divine creation.) But because the world was created as spirit, there are still bits and pieces of spirit in it. These have been imprisoned by what is called matter, and the only way to liberate them is to know the secret gnosis, or knowledge. A spiritual being must come from the other side and awaken humans from their spiritual slumber, their dream. Their spirits are asleep and need to be reminded of their true identity.
But the way is difficult. Humans are insulated from reality by many layers of heavenly realms, each ruled by an evil power who tries to bar the way to salvation. The messenger, thought by early Christian Gnostics to be Jesus Christ, holds the key that will unlock the bars. He had the spiritual "password," so to speak, and taught it to his disciples, who passed it on to others. In other words, Jesus came to Earth to remind people who they really were and to teach them how to return to that state.
This opened a tricky theological quagmire. Christ was a heavenly messenger. Since matter, including bodies, are evil, Christ could not have had a human body. Gnostics living at the time of Jesus pointed to the fact that before returning to heaven Jesus appeared in locked rooms and seemed to be in many far removed places without needing time to travel.
Orthodox critics were appalled at this thought. The whole point of the Gospel, according to them, was that God became a man just like the rest of humankind.
Maybe Jesus did have a body, countered the Gnostics, but it was certainly not like ours. That would have put him under the same power of evil that has entrapped humankind. Gospels were written claiming that one disciple or another noticed that sometimes Jesus seemed soft and airy and at other times rock hard. He only "seemed" to be human. These theories explaining Christ's body earned the Gnostics the title Docetists, which means "to seem."
Questions about the illusory or evil nature of matter naturally led to questions of ethics. How is a person to live? What are the rules of righteousness? Some Gnostics became extreme ascetics. They felt they needed to punish the body. Others became libertines. Since the body didn't matter, they let it follow its desires.
For a hundred years the battle persisted. Eventually, because the majority of Christian theologians thought Gnosticism denied such bedrock doctrines as Creation, incarnation, and resurrection, to say nothing of ethical behavior and lifestyle, a statement of faith was formulated to lay the controversy to rest.
In about 150 ce, probably in Rome, the series of questions then called a "symbol of faith" was composed and recited to baptism candidates to distinguish Gnostic Christians from what became known as orthodox Christianity.
Do you believe in God, the Father Almighty?
Do you believe in Christ Jesus, the Son of God, who was born of the Holy Ghost and of Mary the virgin, who was crucified under Pontius Pilate, and died, and rose again at the third day, living from among the dead, and ascended unto heaven and sat at the right hand of the Father, and will come again to judge the quick and the dead?
Do you believe in the Holy Ghost, the holy church, and the resurrection of the flesh?
Anyone who said "yes" to all three questions was baptized. This was the genesis of Christianity's oldest statement of faith, the Apostles' Creed.
It was supposed to mark the end of Gnosticism, but it didn't. One of the ideas that refused to die was that of Jesus teaching a secret wisdom to his disciples. If the apostles passed on this wisdom to others, it follows that those who received such wisdom would be the leaders of the church.
Even though bishops denied any secret wisdom and church leaders denied being entrusted with the gnosis, the idea persisted among the laity. Partly as a disclaimer, to show being appointed bishop was not about secret wisdom, churches began to keep lists, showing the unbroken line of orthodox apostles to present-day bishops. Thus, apostolic succession was born and continues to this very day in Roman Catholic and Anglican traditions. Second-century churches could thus show an unbroken line dating back to the time of Christ in a way Gnostics could not. This, by the way, was the beginning of the term "catholic." "Catholic" means "universal." By calling itself the Catholic, or universal, Church, early Christians were emphasizing the fact that they were the bearers of a message open to all, not just those who knew the secrets. Catholic also means "according to the whole." The message of Christ came through the complete message of all the disciples, not secret knowledge given only to one.
It is a supreme historical irony that this deliberate move to include all the apostles, this effort to become truly "catholic," would, centuries later, come to be centered on the person and authority of one disciple-the apostle Peter, considered to be the first pope.
Sources: Gonzalez, Justo L. The Story of Christianity. 2 vols. New York: Harper & Row, 1985.
