Leon Morris on the God of peace and peace with God

So completely is the idea accepted that peace comes from God that He can be referred to as 'the God of peace', an expression which implies that the bringing about of peace is a characteristic feature of His activity. A particularly instructive example is Romans 16:20, 'And the God of peace shall bruise Satan under your feet shortly'. In the very sentence in which He is designated 'God of peace' that same God is pictured in warlike activity of bruising Satan. Nothing could more graphically illustrate the fact that peace in the New Testament is not simply the absence of war. It is a much more positive concept, and one which, as here, may be compatible with struggle. It stands for spiritual well-being at the highest level, a prosperity of soul resulting from being in right relationship with God ... Christ, by His atoning death, has done away with enmity. He has brought about a comprehensive peace, one which includes complete wholeness spiritually, and right relations with God issuing in right relations with man ... The New testament does not regard man in his natural condition as at peace with God. Rather, so long as he is outside Christ, he is at enmity with God ... In the Person of Jesus Christ He intervened and brought about a new state of affairs and it is this which is called 'peace'.

(Morris, Leon. The Apostolic Preaching of the Cross. Grand Rapids: Eerdmans, 1965. Print. 241-3)