Peace denotes the capacity to bear success and failure, joy and misery, defeat and victory, with equanimity. Man is at peace, only during sleep. For, at that time, the senses are inactive, the mind is inert and unattached to senses or their targets. So when the senses are made ineffective to drag the mind out, man can attain peace.
(From : Sai Veda, The Word of God, sayings of Bhagavan Sri Sathya Sai Baba)