Ancient Gnosticism
The Greek word for knowledge is gnosis, and it is from this word that the approach towards understanding reality that was prevalent by the first century is called gnosticism. It was a combination of religion and philosophy, and it was attractive to those who wanted a more intellectual, sophisticated approach. A gnostic could pride himself on the knowledge he possessed, especially if it was packaged round the idea that this was exclusive knowledge.
The essential belief of gnosticism was that the true God was beyond man's understanding, even with deep and prolonged meditation. But – gnostics believed – one could get in touch with lesser divine beings, who were intermediaries between mankind and the true God. The techniques for achieving this were, of course, secret: only available to the initiated, through secret rituals, which would be progressively revealed as one moved up the ladder of knowledge.
In this very oversimplified definition of gnosticism one immediately recognizes parallels from every age, including the present one. How wonderful to have secret knowledge, to be a member of an exclusive group. How seductive and attractive, how boosting of one's ego.
Gnosticism came in many flavors: pagan, Jewish, and from the first century onwards, even Christian. In fact the early Christian church often saw its main threat, apart from the very obvious intermittent persecutions, to come from those preachers who would add their own gnostic interpretations to the fundamental Christian message: that in Jesus Christ the Word had become flesh and dwelt among us. The challenge to the multiple intermediaries of gnosticism was the Christian message that there was only one intermediary, who was both Man and God. The doctrine of the incarnation as a unique and real event was a logical challenge to the mind. How could any being be both Man and God. So there were those who taught that Jesus was only Man, and got 'adopted' into divinity. Or, at the other extreme, that Jesus was indeed divine, God on earth pretending to be human, and so only 'seeming' to be human.
How the early Church recognized these threats and dealt with them, ultimately by producing the authoritative statements of faith we usually refer to as the Nicene and Athanasian Creeds, is a matter that can be studied in the many history books that have been written.
The point of giving this (again I must insist, very superficial) account is to raise awareness of the whole question about truth and reality: how can we know the truth? How can we know reality?