"Therefore, since we have been justified by faith, we have peace with God through our Lord Jesus Christ" (Romans 5:1).
"And let the peace of God rule in your hearts, to the which also you are called in one body; and be ye thankful" (Colossians 3"15).
The Bible describes two kinds of peace: peace OF God and peace WITH God. They sound very much alike, but they actually are quite different. Peace with God is a place of position; while peace of God is an experience that's only available after having peace with God.
Peace with God is the foundation of our walk with God. It's just the beginning.
It's not a feeling, but a fact. Before we come to Christ, our sin places us in a state of opposition to God. But when we trust in Jesus for salvation, when we become a believer and a Christ follower, that hostility ends. Romans 5:1 says we are justified--declared righteous--by faith, and as a result, we have peace with God.
Look at "Peace with God" as your new standing with the Father. He becomes your Father; your God. It's not something we work for; it's something Jesus secured for us on the cross. Romans 10:9 declares if we want peace with God, we must confess with our mouth the Lord Jesus, and believe in our heart that God raised Him from the dead, and we shall be saved.
It's that easy. Peace with God happens when our standing with God changes. The hostility is removed and we're justified by faith in His redeeming power.
Once we have peace with God (salvation), we can experience the peace of God. This is the inner calm that guards our hearts and minds even in life's storms. It comes from believing God is able to bring us safely to the other side of the circumstance.
It's after we have "peace with God" that we can experience the true meaning of "peace of God"; a calmness that supersedes the storm. This peace, the peace of God, is something we feel. It's something we experience in difficult and anxious times. It's something we "lean on" in troubling times.
The need for peace is something we all understand and something we all long for - especially when circumstances of life knock the life out of our sails: sleep is impossible and it looks like we have no hope of peace. Philippians 4:7 describes the "peace of God" as a peace that surpasses all understanding. It doesn't always make sense to those around us, but it anchors our soul. This peace grows as we bring our worries to God in prayer and learn to trust His promises.
Rest in the peace you have with God because it's unshakable. And seek the peace of God. I can only tell you what I've experienced in my life and that is: understand the difference in peace with God (our position) and peace of God (a felt, spiritual calmness) because that's what can transform our walk with Christ. Turbulent times come, but the "peace of God" gets us to a place of rest and trust.