We see God in the particular form in which we worship or meditate on Him. God, out of compassion, assumes form and appears to His devotee. If the devotee approaches God with the attitude of a son, he realizes God as his Father; if we meditate on Him as Sri Krishna or Shiva, then He assumes the form of Bhagavan Krishna or Mahadev Shiva and appears to us. So God can be experienced in the depth of the heart as the innermost thought. However, even these experiences are not considered to be of permanent value if they do not completely remove the source of our troubles and bondages.
God may be experienced not only as the inner Self, but also as the all-pervading Self. A person does not realize God objectively. The innermost being that becomes God is not apart from anything. It is the one Essence of the universe. The essence of mind and matter is identical. And that Reality, which is the innermost Self of everything, cannot be objectified. An individual realizes God by realizing his very being in the in most depths of his being. So God realization means realizing one’s own essential unity. When a person realizes God, he becomes unified with God. This unification or unitary experience is called samadhi.
In each and every kind of knowledge, there is always some distinction between the knower and the known. It is only in the state of samadhi that all distinctions between the knower and the known are coalesced into the one Existence. It is only then that the realization of God is possible. The God that is known in this case is the inner most Being. And that is the kind of realization that brings about complete freedom. That is the illumination of the Chosen Ones. I am referring particularly to those rare individuals who realize God as the innermost Self untouched by the psychophysical system.
Then again, there are two kinds of samadhi: savikalpa and nirvikalpa. When a person realizes God as the one all-pervading Reality in the state of samadhi, his mind becomes completely tranquil and is suffused with the light of divine Consciousness. After that realization, the person may come back from that august state to the ordinary level. But though he may not look extraordinary outwardly, he is no longer an ordinary person.