The group called agnostic is rarer than the groups of people that are agnostic atheist or agnostic theist. Agnostics seem to be closer to a radical skeptic, or Pyrrhonist, that reserves judgment on everything. But an agnostic atheist or agnostic theist share a similar epistemological judgment that God cannot be absolutely known or proven in any philosophical or scientific way, but can be believed in or disbelieved in by personal convictions.
It's both intellectually dishonest and disingenous to try to confuse weak and soft atheism as classifications of degree of disbelief with agnosticism and gnosticism, which are concerned with whether knowledge about God in itself is possible, which I don't think even Christians believe in; any knowledge about God is revealed and indirect, not direct in seeing God face to face.