There is an outer and an inner significance to the descent of the Avatar. The outer action is frequently described as upholding the Dharma, destroying the forces of opposition and hostility and uplifting and encouraging those who seek to live according to Dharma. Sri Aurobindo reminds us that this is only one aspect of the work of the Avatar; and further, that the concept of Dharma, often boiled down to its ethical connotation, is in reality a much more complex concept that embodies ethics, morality, duty, and spiritual action aligned with the deeper purpose of one’s existence.
“The outward action of the Avatar is described in the Gita as the restoration of the Dharma; when from age to age the Dharma fades, languishes, loses force and its opposite arises, strong and oppressive, then the Avatar comes and raises it again to power; and as then things in idea are always represented by things in action and by human beings who obey their impulsion, his mission is, in its most human and outward terms, to relieve the seekers of the Dharma who are oppressed by the reign of the reactionary darkness and to destroy the wrong-doers who seek to maintain the denial of the Dharma.”
The many stories told about the Avatars of Vishnu illustrate this concept, as “…the Avatar descends to deliver the good and destroy the wicked, to break down injustice and oppression and restore the ethical balance of mankind.”
This of course is only one aspect of the role of the Avatar and is actually neither the most significant nor is it universally the case that the Avatar must do outward battle in a worldly sense with forces arrayed against him. The tales, however popular, only touch on a portion of the Truth, not the entire meaning of the Avatar’s birth.
Sri Aurobindo, Essays on the Gita, First Series, Chapter 17, The Divine Birth and Divine Works, pg. 160