“Thou wilt keep him in perfect peace, whose mind is stayed on thee: because he trusteth in thee”. Isaiah 26:3
What is signified by a mind “stayed on” the Lord? At least three things.
First, to make the Lord the Portion of my soul. All around us are those vainly seeking contentment in things: such as money, and what it can buy, social prestige, fame, worldly pleasures, etc.—all of which are broken cisterns which hold no water. Only the One who made us can satisfy the heart; only as our affection is set upon “things above” do we drink of the Fountain of living waters. Just in proportion as “Delight yourself also in the Lord” (Psalm 37:4) will “perfect peace” be mine now.
Second, to receive from God’s hand whatever enters my life. I need to cultivate the habit of looking beyond all secondary causes, all intermediary agents and human instruments, recognizing that “of Him, and through Him, and to Him, are ALL things” (Romans 11:36). “Cease from man” (Isaiah 2:22); conclude no more, that it is Satan who is seeking to disturb your rest; but say, “The cup which my Father has given me, shall I not drink it!” (John 18:11). Just in proportion as we are enabled to say from the heart “It is the Lord—let Him do what seems Him good to Him” (1 Samuel 3:18) will “perfect peace” be ours in this world of sin and turmoil.
Third, to leave the future entirely with God. And why not? Are not my “times” in His hand (Psalm 31:15)? Has He not graciously cared for me and faithfully supplied my every need hitherto? Then why be fearful of what lies ahead? Has He not promised never to leave nor forsake me! Just in proportion as I live a day at a time, and “Do not worry about tomorrow” (Matthew 6:34) will “perfect peace” be mine even now. But each of these three things is dependent upon the exercise of FAITH; as the text says, “because he trusteth in thee.” Oh, to know more of this experimentally! – A.W. Pink