Our Scripture reading today is Philippians 4:6-7.
Verse 7, "And the peace of God, which passeth all understanding, shall keep your hearts and minds through Christ Jesus."
Quite possibly you have heard someone speak of the importance of guarding your heart and mind.  We should not allow certain things to enter into our heart and mind for they will affect the way we live and think.  The Apostle Paul reminds us of the best way to "keep" our hearts.  The word, "keep" is translated from the Greek, phroureō which means to watch, guard or protect.  While we can try and try all we want to keep our heart and mind, only the peace of God will thoroughly do the job.  “What is God’s peace? The unruffled serenity of the infinitely-happy God, the eternal composure of the absolutely well-contented God.” (Spurgeon)
Since we cannot explain the peace of God, it must be experienced.  The only way to experience the peace of God is to go through trials.  While the peace of God is present at anytime, we are able to recognize it when an unexpected difficutly comes into our lives.  God's peace will be there to guard our heart and mind.  It is then that while we cannot lean on our own understanding, we can put our complete trust in the Lord.