Gnosticism is a philosophical worldview that stresses special knowledge.  The word comes from the Greek gnosis meaning knowledge.  Gnosticism was prevelant in the first century during and after the time of Christ.  It maintains that matter is evil and spirit is good.  Because matter is bad human souls, in a sense, are trapped in a material world.

Gnostics maintained that they had special knowledge about God which enabled them to understand the human condition as it relates to the world.  This helped them to deny the world, by asserting that the good human spirit need not be restricted by the evil material world.

Early Gnostics taught that God was so perfect that he could not have anything to do with the physical world -- including its creation.  Therefore, God made a demiurge, a lesser God through which the world was created.  Gnostics considered themselves superior to early Christians and believed that this lesser God was the God of the Old Testament.

Gnosticism traces its roots back just after the beginning of the Christian Church. Some researchers state that evidence of its existence even predates Christianity. Whichever the case, the error of gnosticism had affected the culture and church of the time and possibly even a earned a mention in 1 John 4.

The word "gnosticism" comes from the Greek word "gnosis" which means "knowledge." There were many groups that were Gnostic and it isn't possible to easily describe the nuances of each variant of Gnostic doctrines. However, generally speaking, Gnosticism taught that salvation is achieved through special knowledge (gnosis). This knowledge usually dealt with the individual's relationship to the transcendent Being.

A more detailed Gnostic theology is as follows. The unknowable God was far too pure and perfect to have anything to do with the material universe which was considered evil. Therefore, God generated lesser divinities, or emenations. One of these emanations, Wisdom desired to know the unknowable God. Out of this erring desire the demiurge an evil god was formed and it was this evil god that created the universe. He along with archons kept the mortals in bondage in material matter and tried to prevent the pure spirit souls from ascending back to god after the death of the physical bodies. Since, according to the Gnostics, matter is evil, deliverance from material form was attainable only through special knowledge revealed by special Gnostic teachers. Christ was the divine redeemer who descended from the spiritual realm to reveal the knowledge necessary for this redemption. In conclusion, Gnosticism is dualistic. That is, it teaches there is a good and evil, spirit and matter, light and dark, etc. dualism in the universe.

What we know about Gnosticism is gained from the writings of Irenaeus, Hippolytus, Tertullian, Origen, and some later manuscripts discovered in the eighteenth century such as the "Codex Askew, Codex Bruce, the Berlin Gnostic Codes and, most recently, the Nag Hammadi collection." Nag Hammadi is a town in Upper Egypt near ancient Chenoboskion and 13 codices discovered were discovered about 1945.

The danger of gnosticism is easily apparent.  It denies the incarnation of God as the Son. In so doing, it denies the true efficacy of the atonement since, if Jesus is not God, He could not atone for all of mankind; and we would still be lost in our sins.

There is debate whether or not this is a Christian heresy or simply an independent development. The evidence seems to point to the later. Nevertheless, the Gnostics laid claim to Jesus as a great teacher of theirs and as such requires some attention. It is possible that 1 John was written against some of the errors that Gnosticism promoted.