One should take care to distinguish the unit (or individual) from the group (or -ism). For example, there’ve been ‘Gnostics’ in a number of societies and religious traditions that pre-date Christianity, but the term ‘Gnosticism’ only appeared a few centuries ago.

That said, it seems to me that two distinct thought processes are involved when gaining knowledge, as opposed to adopting a belief. The former occupies a seemingly endless spectrum—seeking knowledge inevitably leads to the realization that there is more (much more) to be learned—whereas the latter can be distilled to a simple binary: one either accepts (believes) a proposition, or rejects it.

It is important to note that, when addressing the topic of the existence of God, the theist often insists on a reliance of the same evidence that the atheist has examined. However, the theist’s position is, “I believe,” while the atheist’s position, properly stated, is, “Based on the evidence, I remain unconvinced.” Note that the atheist’s position isn’t, “I don’t believe,” rather, it is “I am not convinced.” This is not a choice between ‘guilt’ or ‘innocence.’ The atheist examines the evidence and finds that God is, effectively ‘not guilty of existence.’

Regrettably, what is often called ‘personal experience’ can trump observations of fact, effectively bypassing the imperative for objective, quantifiable corroboration. And it is here that we come down to the mental process known as ‘faith,’ which Peter Boghossian has noted is “belief without evidence,” or “pretending to know things you don’t know.” It would seem that no amount of reasoning, observables or rational discourse can overcome that abrogation of intellect exacted by religious faith, or what the great agnostic, Robert Green Ingersoll, referred to as “that unhappy mixture of insanity and ignorance.” Rarely critically examined, and frequently heralded in the political sphere, one’s personal faith allows for a universe of intemperate reasoning and outright mischief!