Anger and hatred can be used to ward off the evil that stalks the spiritual aspirant. Be angry at the things that hamper you. Hate the habits that brutalize you. Cultivate the supreme knowledge (Jnaana) and visualize the Lord in all beings, things and activities. That will make your human birth worthwhile.

- Sathya Sai Speaks,  Vol 3, Ch 23, Sep-8-63 

"Be in the world, but not full of it.  That is the secret to a successful life." - Baba