Like all Christianity, gnosticism is different things to various believers. Gnostic=to know. There is no one gnosticism, and each distinct sect has its own beliefs.
About the only thing I know about Gnostics is that it is a variation of Christianity combined with some Greek ideas that the physical body holds you back from progressing and the you will reach a higher level of existence once you cast off your physical body.
Which to me is really funny that Christians would adopt such an idea when we believe that Christ was resurrected and took his body up again. Of course it was a glorified perfected body, not quite the same kind of body we have, but thanks to him someday we'll all get the same.
Gnostics believe that an evil God created all matter & that only the spirit is good.
I myself am a Christian & believe that God is a good, loving, faithful, merciful, forgiving, & compassionate God who sent his one & ONLY son to die for the world & me. What a sacrifice! To give your only child for the world.
Wow.
Gnostics believe that one is saved by possessing a type of mystical knowledge called nosies. Beyond that, different varieties of Gnosticism vary quite a bit.
Gnosticism is a very old form of Christianity. A lot of the specific tenants are not known because of a campaign of destruction by the orthodox Christians once they got into power in Rome. The basic views seem to be that there are two deities: a good one and an evil one. The evil one was the creator of the world and Jesus was sent by the good one to save us. The Gnostic's also believed that there were secret teachings that Jesus gave to only a few of the apostles as well as some of the women in his circle of followers. The Gnostic's tended not to heed the power of the clergy and focused on personal revelation. This is one reason the orthodox clergy didn't like them. They were also much more open to women in power than the orthodox.
The Gnostic's had many writings that they held to be authoritative (gospels) but which were rejected by the orthodox when the New testament was assembled. Some of these alternative gospels have been found. Just yesterday, the Gospel of Judas was released in translated form. Others include gospels attributed to Mary and to Thomas.
Gnosticism is: "A religious orientation advocating nosies as the way to release a person's spiritual element; considered heresy by Christian churches"
nosies is: "Intuitive knowledge of spiritual truths; said to have been possessed by ancient Gnostics"
- WordWeb
"Question: "What is Christian Gnosticism?"
Answer: Christian Gnosticism is the belief that one must have a "nosies" (from Greek "Gnosko," to know) or inner knowledge which is mystical knowledge obtained only after one has been properly initiated. Only a few can possess this mystical knowledge, limiting the number of those "in the know". It is a heresy that Paul battled against in some of his letters to the churches and was soundly condemned as a heresy in the first century church (40-100 A.D.). It is resurrected today as the forerunner to the New Age Religion where virtually anything goes and "religion" takes on many forms, especially the mystic Eastern religions that are so prevalent today.
Gnosticism today seems to provide a lot of the form and color for the New Age portrait of Jesus where Jesus is seen as the illumined Illuminator: one who serves as a cosmic catalyst for others' awakening. As such it is as false and heretical as the Gnosticism of the first century and needs to be roundly condemned for the heresy that it is."