To begin with, Gnosticism was a title ascribed to a widespread tendency and movement toward spiritual elitism. That the sects at Corinth "were inclined to pride themselves on the possession of profounder wisdom and deeper mystical experiences... [and] regarded their fellow Christians as inferior beings who had not risen to the truly supernatural heights" is surely an adequate indication of their spiritual aristocracy.
What is more is that the notion of a spiritual superiority among the Gnostics entailed a sincere belief in the possession of arcane knowledge. That is to say, there was a direct correlation between the worth, status, and importance of a person and the amount of mystical, or esoteric knowledge they had. Accordingly, spiritual knowledge was priceless, while the rudimentary, even base understandings of mere material things gradually became scornful. The truly knowledgeable person is in possession of new insights and spiritual intuitions. "Like circles of artists today, gnostics considered original creative invention to be the mark of anyone who becomes spiritually alive." Thus an ever-widening gulf developed between notions of spiritual realities and the immediate material reality. The former was sought after and prized, while the latter earned by degrees less favour.
Eventually, "most Gnostic schools [became] thoroughly dualistic, setting an infinite chasm between the spiritual world and the world of matter, which [came to be] regarded as intrinsically evil." This ontological duality between the divine and human, body and soul, spiritual and material necessitated answers to why there was a material reality at all. What had happened that the divine, or spiritual reality would mingle at all with coarse and crude matter? Here the Gnostics can be heard echoing the refrain of the Psalmist "what is man that you are mindful of him, and the son of man that you care for him?" (Psalm 8:4, ESV)*
Such eschatological questions led the principle Gnostics of the first two centuries to formulate highly complex, even philosophical treatises that would preserve the integrity of the wholly transcendent Supreme God, while giving answer to the unfortunate subsistence of material reality. Most notably Saturninus, Basilides, Valentinus, Carpocrates, and Marcion all shared similar notions of a divided divine reality being in part the reason for the lowly material reality. "[When] they tried to explain how the material order came into existence, they agreed in refusing to attribute its origin to the ultimate God, the God of light and goodness." Thus for the Gnostics, salvation was not a matter of escaping the final consequences of sin, it was the anticipated mediation of
...a saviour from the divine sphere who descends in order to impart the knowledge that brings release to the spiritual element in men. This knowledge is knowledge of the truth about oneself and one's situation in relation to the world and to one's heavenly origin. By this one can be assured of enlightenment and consequently of present liberation and future ascent to the pleroma [fullness] when the body has been cast off at death.If salvation then was spiritual epiphany via imparted knowledge, then physical practices such as animal sacrifice (as noted in the Old Testament), or even Christ's sacrifice would be abhorrent. Such dependence on physical means for spiritual renewal was the province and possession of the unenlightened, the crass and spiritually slumped. Thus the Christian doctrine of Christ's resurrection was not acceptable to the Gnostics and they constructed teachings that were consistent with their disdain for matter, and by implication their disgust for the notion that God would take on flesh.
Gnostics rejected the assertion that Christ was the incarnate God. Even groups that seemed to reflect an almost orthodox Christianity,
...such as the groups founded by the Egyptian Basilides and by the Platonist Valentinus of Rome, the Gnostic attitude to matter as alien to the Supreme God required the rejection of any genuine incarnation. The divine Christ (they held) might have appeared to blinded worldlings as if he were tangible flesh and blood, but those with higher insight perceived that he was pure spirit and that the physical appearance was an optical illusion and mere semblance (dokesis, whence this doctrine is labelled Docetism).Christ, the Gnostics maintained, if he were God, would only have appeared to be human to the spiritually dull. In reality, Christ was a pure spirit unpolluted by the taint of matter.
This particular notion of Christ only seeming to be a man was not held by all Gnostics but became a key sign in identifying Gnostic tendencies amongst the religious. It was known as docetism, from the Greek word δοκέω (dokeo). In essence, the docetic assertion was that Christ was simply a very real or convincing phantom, and not at all a man. Less convinced Docetists advocated a notion remotely similar to the hypostatic union of Christ believed by adherents to apostolic, or orthodox Christianity. In short, they maintained that there was a man named Jesus upon whom the divine λόγος (logos), or Christ descended at his baptism, and ascended at his crucifixion, leaving only the man Jesus to suffer physical pain. The divine Christ resided for a while in the body of the man Jesus; a participation between the divine and physical realities. This temporary condescension of the divine λόγος served to illustrate Jesus as the proper "model for the gnostic savior."
Citing Christ as an exemplar for the Gnostic notion of a saviour implicitly commends itself to large-scale schisms within the nascent church of the first two centuries. Gnostics believed themselves to be Christian, ergo they would incline themselves to occasional assemblies with other Christians, not for the purpose of learning from current leaders but to enlighten the dim or deceived with their understanding of divine reality. So while the early church reeled from Nero's pogroms against Christians (ca. 65 AD), Domitian's famous three charges of atheism, cannibalism, and licentiousness (ca. 81-96 AD), and the Decean and Diocletian persecutions (ca. 250; 284-304 AD), the specious doctrines of the Gnostics winnowed their way into the laity and clergy of the first two centuries.
The resultant effect was, as Quasten puts it that "Gnosticism threatened [the church's] spiritual foundation and its religious character." That the early church was attempting to structure and stabilize itself is understood implicitly from its description "early church." Hence the weight of assertions levied within the circles of early Christendom by the Gnostics served to unhinge peoples' confidence and faith. So as not to be misleading, however, it is important to point out, as Kelly does, that "there was no single Gnostic Church," and therefore no direct competition, or visible entity for the early Christian church to make its rejoinders. Staving off the influence of the Gnostics then, was a bit of a hit and miss activity that took the better part of one hundred and fifty years to finally succeed.
 Chadwick, Henry, The Early Church Rev. ed. (London: Penguin Book Ltd., 1993) 33-34.
 McKechnie, Paul, 153
 Pagels, Elaine, 22
 Kelly, J.N.D., 26
* All Scripture references taken from The Holy Bible, English Standard Version (Wheaton, Illinois 60187: Crossway Bibles, 2002)
 Kelly, J.N.D., 26
 Cunliffe-Jones, Hubert, ed. A History of Christian Doctrine (London: Continuum T&T Clark, 1978) 29.
 Chadwick, Henry, 37
 Ibid. 37
 Bruce, F.F., New Testament History (Garden City, New York: A Doubleday-Galilee Book, 1980) 416. "The Docetists, regarding matter as inherently evil, could not believe it possible for a divine being to come into such close association with the material order as was implied in incarnation in a human body. Jesus, as the manifestation of deity on earth, could not have a real human body; he only seemed to have one."
 Grant, R.M., 36
 Dr. John Stephenson, "The Gnostic Crisis" The Patristic Age HITH 7P00, Concordia Lutheran Theological Seminary, October 18th, 2004.
 Dr. John Stephenson, "The Age of Persecution" The Patristic Age HITH 7P00, Concordia Lutheran Theological Seminary, September 16th, 2004.
 Quasten, Johannes, 254
 Kelly, J.N.D., 26
(Category: The Church: Christian History)