Just as a wheel requires a stationary or immovable hub to rotate, the constantly changing physical world requires a still and unchanging unmanifest existence to sustain itself.
Like us, Arjuna exists at the level of the manifest human body and is concerned about the death of his relatives. Lord Krishna, who was in human form at the time, explains why and how the unmanifest sometimes assumes a manifest form.
He says, “I am unborn, eternal, and the Lord of all beings. Subjugating my nature, I incarnate through my “Yoga-maya”.” (4.6). Through “Maya”—which is essentially a thought—the unmanifest becomes manifest, just as the Divine does. The difference lies only in the levels of consciousness, intent, and compassion.
Sri Krishna further states, “Whenever there is a decline in “Dharma” (righteousness) and a rise in”Adharma” (unrighteousness), I manifest Myself—that is, I appear before people in a physical form.” (4.7). “To deliver the righteous, to destroy the wicked, and to firmly establish “Dharma”, I manifest age after age.” (4.8) Spiritual teachers often cite these verses to reassure everyone that the Divine is close at hand to protect the righteous. A simple, literal interpretation suggests that whenever righteousness declines and unrighteousness or evil rises, He will descend to Earth in the form of an “Avatar” (incarnation).
On a deeper level, the question arises: what exactly are “Dharma” and “Adharma”? Who are the righteous and who are the wicked? What distinguishes them? In the case of the righteous and the wicked, it is not the individuals themselves, but the qualities of saintliness or wickedness within them that need to be preserved or destroyed. Similarly, “Dharma” and “Adharma” can be viewed as directions of travel—either towards that eternal state or away from it. Divine assistance is required to change one’s direction along this path