Isaiah 26:3

In perfect peace. Literally, “in peace, peace.” Perfect peace will be the inheritance of the saints in the kingdom of God and it may be the happy experience of God’s children here. Perfect submission to the will of God brings the blessing of perfect serenity. The mature Christian is at peace with God, with himself, and with the world about him. Compare the experience of Paul (2 Cor. 11:23-28; cf. ch. 4:8-10), his philosophy of suffering (2 Cor. 4:17, 18), and his confident assurance to us (Phil. 4:7). Trouble and turmoil may surround us, yet we enjoy a calmness and peace of mind of which the world knows nothing. This inward peace is reflected in a cheerful countenance, an unruffled temper, and a vigorous, glowing experience that stimulates all with whom we come in contact. The peace of the Christian depends not upon peaceful conditions in the world about him but upon the indwelling of the Spirit of God in his heart (see on Matt. 11:28-30; John 14:27).