The Seer & the seen
Shunyata, emptiness, means empty of name and form, but never empty of the Witness. "You can deny everything, but you cannot deny the existence of the denier." How do we know there is a void? Because someone saw it; otherwise how would we know about it? Nothing doesn't exist. No one says "I don't exist," they say "I am, I am!" Even when one is dying, one is experiencing "I am-ness." We know we have had a series of lives because we were there to witness our births and deaths. Sanskrit has words for this, like smriti betu — a causal memory around inner functions and formlessness.
The Seer is able to see a plethora of principles operating — no matter how they are masquerading — like domination, gaining/securing/protecting wealth, the tattvas, the siddhis, etc. — as a result of being able to range widely in the Cosmic Mind. This ability is based upon nonviolence, which has proven that the Self is birthless and deathless. Therefore, he is no threat to others, and nothing can threaten him. This, combined with trigunatita (which means the ability to put the mind on or off objects at will) grants mental acuity and insight with great flexibility in perception.
We teach the kids that Spirit and matter do not mix by using a jar of oil and water. We have them shake up the jar. Do they mix? "Yes" they say. But 45 seconds later it has separated again. Those 45 seconds might as well be 45 lifetimes if the soul does not recognize the difference between nature and the Soul.
Patanjala, Sankhya, Buddhism, and Advaita Vedanta are all non-theistic. If one likes God with form one can anthropomorphize the cosmology and populate states of awareness with deities and call them heavens. But you can take all this from the standpoint of Consciousness and its levels as well — all formless. Still, it cannot be denied that the mind has power to congeal things.
We have a chair in the waking state and in the dream state. But what is it in the deep sleep state? It is an idea that has not vibrated yet. Think of deep sleep as a Cosmic Chest of Drawers presided over by the Mother of the Universe. She hands conditioned awareness over to the Trinity, and out comes the worlds. The reason one remembers nothing in deep sleep is that nothing is vibrating.
Satya/truthfulness, svadhyaya/study of scripture, aparigraha/non-receiving of gifts, and asteya/non-coveting of objects — together, these equal nondistraction. If you have these you will be able to remember your past lives. Why am I suffering? Why don't I remember my past lives? By not observing these one remains attached to the world, its objects, and is therefore constantly distracted.