The body is a part of prakriti, an aspect of which are the five elements. All human beings are made up of these elements in various permutations and combinations. Yog says that all these elements have an individual and a collective consciousness, meaning thereby that we are all connected to each other and also to all aspects of creation.
Modern Science now accepts that cells which are the substratum of matter, have a consciousness. When they are separated they have the ability to communicate with their other parts, even from a distance. This is what the Vedic rishis have been speaking for many thousands of years. This is also the foundation of Dhyan and communicating with the Gods. In deep states when we go to the core of our beings, then we awaken that consciousness and redevelop the ability to communicate with those cells which were once a part of us; though the cell is dead but its energy still lingers, as energy cannot be created or destroyed, thereby implying that cell mutation is the cause of the physically manifested creation and the energy of the cell is connected to the energy of the entire creation.
How awakened we are to the basic energy of creation depends on our one pointed focus which is further dependent on impurities of the body and thought. That is why the Yams and Niyams become the basis of Yog, as it is through these that we are able to cleanse our body and mind, and energy flows freely leading to the state of merger with the entire creation.
So the foundation of merger is not our intellectual knowledge but our levels of purity and one pointed focus.
A clear way to test your levels is to do a Vedic havan, if it is smokeless, has a divine fragrance, its pictures reveal a clear divine form and you are able to give ONE clear interpretation of the form in the fire then you are on the right track, otherwise you need to travel a lot more…with your Guru.