You will keep him in perfect peace, whose mind is stayed on You. —Isaiah 26:3 NKJV
A calm and serene mind is the mark of maturity in the Believer. The untroubled mind is a mind under God’s control. You and I are not called to control the world—only ourselves.
The person who has learned to direct his thoughts away from the worry and aggravation of his surroundings is a person functioning with Christ at the center of his being. When your mind is stayed or focused on Him, the result is perfect peace.
The disturbed mind is a distrusting mind…its fears so great that any shadow is threatening. Life is out of focus when the heart is out of harmony. But the calm, serene heart produces the fruit of the Spirit—love, joy, peace, gentleness, goodness, faith, meekness, and self-control. How? In 1 Corinthians 2:12, the apostle Paul provides the answer:
What we have received is not the spirit of the world, but the Spirit who is from God, so that we may understand what God has freely given us (NIV).