“Therefore, since we have been justified by faith, we have peace with God through our Lord Jesus Christ.”

What does it mean to be at peace with someone? Peace is friendship. Peace is harmony. Peace is open communication, generosity, kindness, alliance, and trust. It is long-earned and hard-won. We need not look far to see true peace can be fragile in the best of times. But Peace with God? To understand the magnitude of this statement, we must first understand our position before Him.
We were created in God’s image, made to be in communion with Him, but divided by our sin. Adam and Eve’s sin, your sin and mine has opened an uncrossable gulf between us and our Creator. Uncrossable, at least, from our side.
Jesus, by his life, unthinkable death, and astounding resurrection has bridged that divide so that the only requirement of us is that we have faith in his work. And our reward? Peace with God. Peace, which means we are called sons and daughters instead of enemies. Peace, which means we can be set free from bondage to sin.
Peace, which means we can live boldly for Christ, knowing our eternity is certain.
Friends, life will not always be easy, but if you place your faith in Jesus, you will always have peace with your Creator. And that is a peace that will last for ever and ever.
...Philippians 4:4–7
Rejoice in the Lord always; again I will say, rejoice. Let your reasonableness be known to everyone. The Lord is at hand; do not be anxious about anything, but in everything by prayer and supplication with thanksgiving let your requests be made known to God. And the peace of God, which surpasses all understanding, will guard your hearts and your minds in Christ Jesus.