Ultimately, the decision whether to believe in GOD, to disbelieve in him, or to remain in doubt about his existence depends on people’s personal tendencies towards the existence of GOD. The question is whether it is possible to ascend from the same inclination of the heart to the ontological summit and make a truthful claim in relation to this reality.
Agnostics retire in advance from the race and do not try to reach the same summit. They remain on the floor of personal inclination, or at the most climb to the floor just above it.
Believers and atheists both try to ascend. But for believers the way there is open, at least theoretically. If they manage to climb to the second floor and claim that there is good evidence for the existence of GOD, then the next required step is to determine based on this evidence, that GOD exists. Whereas atheists, on the other hand, cannot climb to the second floor and claim that there is no evidence for the existence of GOD (because it is such), and, even if they manage to get there and claim it, they have no possibility of climbing from there to the ontological floor, and determining that GOD does not exist. It is possible that GOD exists even if there is no evidence for his existence. Therefore, the obvious conclusion for atheists is to join their agnostic friends in the lack of knowledge about GOD. But they do not join agnostics at that juncture. They would rather define themselves as atheists, thus adhering to the ontological claim that GOD does not exist (since this is the only difference between atheists and agnostics). Therefore, because of this, atheists purport to make an ontological claim for which they have not the slightest justification.