The concept of peace in the Bible is a varied one. For example, the Bible talks about inner peace, relational peace, world peace and peace as one of the 'fruit of the Spirit'.
Above all is that fact that Jesus is the Prince of Peace and the Gospel is a gospel of peace; a reconciliation between God and His former enemies.
To know Jesus is to know peace.
An article based on this sermon: 'The ‘shalom’ (peace) of Jesus'.