Peace is a function of righteousness. Righteousness is a function of obedience of faith (both at salvation, when it is imputed, and experientially, when it is imparted). Peace reigns in the heart and soul of God.
When we subject or submit this body to God's purposes and not our own, we can be a light on a hill to a lost and dying world, a physical example of Christ's love, even in persecution. Php 1:20, 2Co 4:10