Agnosticism is the position that the existence of God, or the ultimate nature of reality, is not known — and perhaps not knowable — with the tools available to human reason. It is not weakness or indecision but an epistemically rigorous stance: the refusal to claim certainty where certainty has not been earned. In this sense agnosticism shares something with the apophatic theology of the great mystics, who also insist that the divine exceeds all concepts, including the concept of its own existence — that the deepest honesty about the sacred is the honesty of not-knowing.
Each step builds on the last.