The essence of mind is only awareness or consciousness. When the ego, however, dominates it, it functions as the reasoning, thinking or sensing faculty. The cosmic mind being not limited by the ego, has nothing separate from itself and is therefore only aware. This is what the Bible means by "I am that I AM".
The ego-ridden mind has its strength sapped and is too weak to resist the torturing thoughts. The egoless mind is happy in deep, dreamless sleep. Clearly therefore Bliss and misery are only modes of mind; but the weak mode is not easily interchangeable with the strong mode. Activity is weakness and consequently miserable; passivity is strength and therefore blissful. The dormant strength is not apparent and therefore not availed of.
The cosmic mind, manifesting in some rare being, is able to effect the linkage in others of the individual (weak) mind with the universal (strong) mind of the inner recess. Such a rare being is called the GURU or God in manifestation.