Mahavishnu took ten avatars or incarnations in order to protect the world through the different yugas or eons. Out of these ten avatars, the Shri Rama avatar and Shri Krishna avatar have gained the most importance... The main purpose of the Rama avatar was to destroy Ravana, the Asura (Demon) King, while the principal aim of Krishna's avatar was to convey the supreme message of the Bhagavad Gita, to vanquish evil and bring back justice and righteousness to humankind... there are also some controversies and questions arising out of the stories herein, which sometimes makes one wonder why Rama and Krishna were so glorified...