When peace, like a river, attendeth my way,
When sorrows like sea billows roll;
Whatever my lot, Thou hast taught me to say,
It is well, it is well with my soul.

(From "It Is Well with My Soul" by Horation Spafford)



Do not be anxious about anything, but in every situation, by prayer and petition, with thanksgiving, present your requests to God.  And the peace of God, which transcends all understanding, will guard your hearts and your minds in Christ Jesus. 
Finally, brothers and sisters, whatever is true, whatever is noble, whatever is right, whatever is pure, whatever is lovely, whatever is admirable—if anything is excellent or praiseworthy—think about such things. Whatever you have learned or received or heard from me, or seen in me—put it into practice.  And the God of peace will be with you.  (Philippians 4:6-9 -- NIV)