From vanaprastha one graduates from partial retirement to a life of total renunciation. This stage of life requires complete control of one’s on senses.
The Sanyasi dedicates his life to the dictates of the Vedas and commits to serving the Supreme Being through serving humanity. There has to be a detachment from all actions, where there is no desire for any form of reward. These are teachings of Vedas, Upanishads and Geeta.
In this sanskāra a person forsakes all material things and starts to lead a life of social service, meditation and contemplation leading to introspection, inner realisation.