The sole meaning of life is to serve humanity by contributing to the establishment of the kingdom of God, which can only be done by the recognition and profession of the truth by every man.
Justice has nothing to do with expediency. Justice has nothing to do with any temporary standard whatever. It is rooted and grounded in the fundamental instincts of humanity.
The Bhagavad-Gita calls on humanity to dedicate body, mind and soul to pure duty and not to become mental voluptuaries at the mercy of random desires and undisciplined impulses.
If the genius of invention were to reveal to-morrow the secret of immortality, of eternal beauty and youth, for which all humanity is aching, the same inexorable agents which prevent a mass from changing suddenly its velocity would likewise resist the force of the new knowledge until time gradually modifies human thought.