According to Buddhism, peace is our birthright. It is inherent in our mind. You see, the mind has two aspects. At the level of absolute truth or in its true nature, mind is utmost peaceful, open, joyful, and enlightened. It sees all simultaneously and as one, through its omniscience. Every being possesses such a nature. That is our ultimate nature, the fundamental basis. Through meditation, we can uncover and perfect this fully enlightened nature, as the Buddha proclaimed when he realized it: I have realized the ambrosia-like Dharma.
It is luminous, profound, peaceful, uncreated and unstained.
The reason we may not always aware of this peace is that we dwell in the conceptual aspect of our mind, not in its true nature. At the level of relative truth or appearance, mind is conceptual, dualistic, and emotional. It perceives mental objects by grasping at them as if they have "selfhood," a truly existing entity. That dualistic concept triggers emotional afflictions such as hatred and attachment and fuels sensational feelings such as suffering, fear, and excitement. Those chains of concepts and emotions tighten the mental grasping and set the wheel of samsaric existence in an endless cycle and cover up our fundamental nature. So, in order to regain our own utmost peaceful nature, we must get rid of the mentality of grasping at the "self."
Source: World Peace Starts from Your Mind – Dharma World, Japan, June, 2007.