Which is the longest epic in the world?

The Mahabharata is the longest epic by far. At about 1.8 million words in total, the Mahabharata is roughly ten times the length of the Iliad and the Odyssey combined, or about four times the length of the Ramayana, the other great Indian epic. The authorship of the Mahabharata is attributed to the sage Vyasa, although it is likely a compilation, written between 400 BC and 400 AD. It relates the story of the Kauravas and Pandavas, who are cousins, and their rivalry over the rights to their kingdom.

The great text of the Hindu religion, the Bhagavad Gita, is contained within it. Krishna, an avatar of Vishnu, is describing to the Pandava warrior Arjuna that the duty of a soldier is to fight; for anyone, doing one's duty is one way to attain self realization.

The great war happens between the rival clans and the Kauravas are destroyed, while the righteous Pandavas regain their kingdom. There are countless complex conflicts and stories within the epic, describing the various aspects of the human condition. There is often the play between duty and righteousness, with the former taking precedence often.