Peace (shalom) is the heart of God. Justice is the mission of Christ. It is the advocacy for and execution of justice in society that allows for true peace and wellbeing (shalom) within creation. The two are not mutually exclusive. Jeremiah gives the people of God hope while they are in exile in Babylon (Jeremiah 29:11). Isaiah (Isaiah 58) confronts the people of God because their fasting (worship) doesn't match their actions (injustice). When we know justice we'll know the peace of God.