gnosis isn’t just knowing something. it’s a specific dynamic or relation between you and knowledge.
to use it in that way is like saying house cat means wild tiger.
Discussion
I think Jesus laid it out pretty well. Simply : gnosis is humility. And humility means your searching without assumptions. IMO that's the key he was talking about in that spat with the lawyerish pharisees.
There is a cosmology in Gnosticism - several, actually, and they don't agree with each other - but that's allegory for psychological processes and spiritual speculation. The conflict between Gnosticism and the churches is basically that Gnosticism rejects answers, while the churches promulgate specific answers that are fraudulent upon inspection.
You've surely found how Christian beliefs have mutated over time... Right?