Every object in the world has two types of properties:
(a) the essential, and
(b) the non essential.

A substance can remain itself, intact, when its "non-essential" qualities are absent, but it cannot remain ever for a split moment without its "essential" property.

The color of the flame, the length and the width of the tongues of flame, are all the "non-essential" properties of fire, but the essential property of it is 'heat.'

The essential property of a substance is called its Dharma .

What exactly then is the Dharma of man?

The color of the skin, the inumerable endless varities of emotions and thoughts - the nature, the conditions and the capacities of the body, mind and the intellect - are the "non-essential" factors in the human personality, as against the Touch of Life, the Devine Conciousness, expressed thru them all. ...it is the truth which is the basis of existence. Therefore, the "essential Dharma" of man is the Devine Spark of Existence, the Infinite Lord.

In and thru such actions, physical, mental and intellectual, a man will bring forth the expression of his true Dharma - his Divine Status as the All-pervading Self.

To live truely as the Atman (roughly, the Spirit/Life in us - neha), and to express Its Infinite Perfection thru all our actions and in all our contacts with the outer (physical, manifested - neha) world is to rediscover our Dharma.

Swami Chinmayananada
explaining
shlok 66, chapter 18
of the Bhagvad Geeta