Man of Honour
Gnosticism is an early Christian Theological Movement generally regarded as heresy by mainstream Christianity rather than a particular philosophical position in the same vein as Agnosticism/Atheism/Theism et al.
That's true, but what can you call the positions which would be described as gnostic if the name wasn't already taken? Agnosticism is the position that a person shouldn't claim something to be objectively true unless they can objectively prove it true, so what do you call the position that a person can claim something is objectively true without objective proof, that something is objective truth because they feel it is?