Gnosticism is when you believe that you have the ability to know whether or not a god exists. It can be applied to both Atheism and Theism. I don't know where you can find statistics for number of adherents.
Gnosticism, which predates Christianity by a few centuries, teaches:
? The physical world is bad
? Only spirituality is good
? Humans are trapped in between
? Salvation comes from knowledge (nosies means knowledge)
? Elitism, only a chosen few will be saved
All of which go against the teaching of Christianity
? The physical world is good. God said so in Genesis.
? Humans are physical and spiritual beings and both natures are good
? Salvation comes from grace and not merit
? God wants all to be saved
Gnosticism is the belief you can KNOW whether or whether not God exists. I'd say 5,880,000 people are Gnostic they "think" they can know whether God exists or not. However, no one can ever know...EVER
Gnosticism comes from the Greek word "nosies" or "knowledge". It began as an early Christian religion which eventually was declared "heretical" by the Church fathers. In 1945 a cache of primary "Gnostic" scriptures was discovered at Nag Hamadi. This included a number of "gospels" that were not included in the modern cannon; the Apocrypha of John and the gospel of Truth, as well as the Gospel of Thomas, some of which may have predated the synoptic gospels . . . . interesting stuff this . . . .
The basic philosophy of Gnosticism is that Jesus was a divine being who only appeared to be human.
Some (not all) humans are imbued with a spark of divinity and the goal of humanity is to return to divinity.
The material world, according to them, is evil.
The other answer, I think refers to "Agnosticism".
Hope this helps,
EDIT: to Imacatholic . . . sir, with all due respect there are a few issues you have totally misconstrued regarding Gnosticism and while there is much in Gnosticism to be debated (and eventually dismissed as simply wrong according to our current way of thinking; line 114 of the Gospel of Thomas for instance) their perspective was one of the then current societal paradigm. Taken out of context as you certainly do you are guilty of falsely trying to influence people into believing only what you believe to be the truth. This is hypocrisy in it's sneakiest and deadliest form. Please stop unduly trying to prejudice everything you do not agree with.
There is not one Gnostic Faith but many. The thread that seems to run through most gnostic faiths is that they thought the God of the old testament was the evil creator of the Earth. Man is not his body. Salvation comes through the denial of the flesh and attention to the spirit. The goal of the gnostic is to shun the trappings of this world and "know" god. This is the root of the idea, "Give up all worldly possessions." "Those who love the world, love not God." You will find many expressions like this in your current New Testament. These are the values of the Gnostic's. Most of the Gnostic texts were eliminated from the bible but the ones we have are easy enough to find. Go to kick ass torrents and type in a search for "Gnostic," you will find complete gospels that you can listen to and professional teachers and lecturers discussing them and comparing the information contained within them to the modern ideas of Christianity.
Modern Christianity is based on the ideas of Plato and the Noe-platonists who followed him. This is a theme that runs throughout the bible and a theme that is not matched in much of the Gnostic writings. Many of the Gnostics do not see Jesus as Devinne or as God himself, some do. The Book of Judas is quite interesting and I really enjoyed the Greater Questions of Mary (Get ready for some shocking stuff.) The Journey of Enoch is a very fascinating book and appears somewhat related to some of the Hindu scriptures. There is a new world of understanding in the exploration of biblical foundations. If this stuff interests you, you can spend a lifetime being amazed. Most everything we call Christian at one time had nothing what so ever to do with the Christian faith. Everything from Adam and Eve, to Exodus and even the Great flood, were just stories being passed around until the Christians got hold of them and turned them into Religious Dogma.
At the most basic level, the terms ?Gnostic? and Gnosticism? refer to a belief that is rooted in special knowledge. Thos in the know are called Gnostics. The term ?Gnosticism? is not ancient. The Protestant Henry More coined the term in 1669 as a polemical name for heresy. More used it to complain about Catholic theology. It is likely the name came from Irenaeus? complaint circa AD 180 about the views he was writing against in his work know as ?Against Heresies.? The work also had the title of ?Expose and Overthrow of What Is Falsely Called Knowledge.? A Greek word for knowledge is ?nosies.? Gnosticism in its broadest sense is about a religious view based on a claim about knowledge.
Indeed, the Greek term for knowledge, ?nosies,? was widely used in appositive and a negative sense in the first century. For example, 1 Corinthians 8:1 uses the word positively and negatively in the same verse. There Paul says, ?We know that ?we all have knowledge.? Knowledge puffs up, but love builds up.? So knowledge is something possessed by those who claim to know Jesus, but the danger is that knowledge will lead to arrogance.
Nock, in his solid article ?Gnosticism,? shows the variety of this general usage for knowledge in the first two centuries. This general use of the term was applied to all types of religious experiences and claims. Then Gnosticism developed a more technical, historical use, applied by both secular and church historians to the views that Irenaeus and others challenged. But a specific definition of this ancient Gnosticism was not developed to the satisfaction of scholars. The problem became so great that a famous conference in 1966 in Messina gathered experts to try to reach an agreed upon definition, but the attempt failed. In 1966 Michael Williams wrote a nook publishes by Princeton University Press called ?Rethinking Gnosticism: An argument for Dismantling a Dubious Category.?