Why only one Guru? What is his/her purpose?

Gurudev Sri Sri - You forget about the Guru. Just walk your path and grow in knowledge. When you benefit and have someone to thank, that is your Guru. The word guide in English came from Sanskrit word Guru. If you want to play soccer, you need a coach. If you want to play violin, you need a coach. Similarly, in life, one needs a coach for managing the mind, and relieving you of the tensions, stress, fear uncertainty, jealousy, greed, hatred and all these negative emotions. So this is the role of a Guru - to relieve you from all negativity and infuse positivity in you.