Don’t get too upset with me yet. We both can agree that agnosticism itself is not a myth.
What has been mythologized (or at minimum, exaggerated) is the religious differentiation between gnosticism and agnosticism.
One Google search will present you with all you might think you need to know. I call it the “scale of knowing” or the “scale of certainty.” It looks something like this:
The issue with graphics like this is that they seek to define these words without attention to the context in which they are being used. Sure, gnosis is the Greek word meaning to know. However, in the spiritual context, it does not mean that someone has total knowledge or certainty about a subject (i.e., God). Who even could? If we had certainty about it, we would have objective proof of the Divine, and there would be no more need for religious debate.
Instead, to be a Gnostic means that someone seeks spiritual knowledge about God.
Therefore, Gnosticism is better defined as a spiritual movement with the acquisition of spiritual knowledge as its core tenet. Gnostics believe in Divine Power through direct spiritual experience and revelations. They fundamentally believe in Divine Power and therefore cannot be categorized as a “gnostic atheist” as the two words are essentially at odds.
One could, however, be an agnostic atheist. While one may not believe in the existence of Divine Power, they are aware that they could be proven wrong.
Gnostics understand that they do not have 100% of the knowledge about God/Divine Power, but they do seek it via internal spiritual practice – because they believe, fundamentally, that God exists.
The reason that early Gnostic Christians were considered mystics was because they welcomed discourse and debate over the exact nature of Divine Power and believed human beings could access that information by turning to the innermost Self.
That fact alone precludes Gnostics from being labeled as “certain” of anything. Gnostics understood, and understand, that the nature of Divine Power is beyond human understanding or cognition. It is a piecemeal revelation, acquired over many years – and perhaps many lifetimes.
Gnosticism is less a scale of knowing and more a description of a faith practice. Let’s squash the “scale of knowing” myth whenever and wherever we can.