Peace through God depends on peace with God

Romans 5:1  "Therefore, since we have been justified through faith, we have peace with God through our Lord Jesus Christ."

There are two aspects to the peace that Paul describes as belonging to believers- peace with God and peace through God.  I think the second type of peace is the one we focus on the most when we consider the concept of peace.  We want our relationship with God to result in peace in our daily lives (thus, "peace through God").  We want the tangible benefit of a relationship with God to be smoothness and harmony in our circumstances. 

While God doesn't promise us a completely peaceful existence in our daily lives, He does promise an overriding peace that doesn't ebb and flow with our circumstances.  This is peace that comes to us by way of our reconciliation with Him. 

"Peace with God" means that we have been fully reunited and reconciled with our Creator.  We are no longer at odds or in conflict.  Our hostility toward Him and our transgressions against Him have been erased, and our relationship has been reset. 

All else pales in comparison to being at peace with God.  Gaining peace through God simply flows from this reconciliation with Him.