What does it mean to 'let the peace of Christ rule in your hearts' (Colossians 3:15)?

from the old testament

• We let the peace of Christ rule in our hearts when we keep our eyes focused on God and trust in Him: "You keep him in perfect peace whose mind is stayed on you, because he trusts in you" (Isaiah 26:3).
• We let the peace of Christ rule in our hearts when we love and obey His Word: "Great peace have those who love your law; nothing can make them stumble" (Psalm 119:165).

from the new testament

• One of Jesus Christ's most comforting assurances in the Bible is His promise to give us peace in this world: "Peace I leave with you; my peace I give to you. Not as the world gives do I give to you. Let not your hearts be troubled, neither let them be afraid" (John 14:27).
• Jesus came to bring us peace (Luke 2:14; John 16:33; Ephesians 2:14–22).
• Philippians 4:6–7 instructs, "do not be anxious about anything, but in everything by prayer and supplication with thanksgiving let your requests be made known to God. And the peace of God, which surpasses all understanding, will guard your hearts and your minds in Christ Jesus."
• Perfect unity among believers in the community of faith is only possible when they allow the peace of Christ to rule in their hearts (Galatians 3:26–29; 5:22–26; Ephesians 2:11–22).
• In Romans 5:1 Paul explains the basis for our peace. "Therefore, since we have been justified by faith, we have peace with God through our Lord Jesus Christ." When we have peace with God, we can also have peace with other people (see, for example, Ephesians 2:1–22; 4:1–32).
• We also let the peace of Christ rule in our hearts by living according to God's Word as demonstrated through Paul and other godly mentors: "What you have learned and received and heard and seen in me—practice these things, and the God of peace will be with you" (Philippians 4:9).

implications for today

False teachers had stirred up division in the church. The way to maintain unity, Paul explains, is to let the peace of Christ “rule,” which means "to be the factor determining the outcome; to arbitrate." In other words, the peace of Christ must act as the umpire of our hearts. Paul had told the Colossians, "See to it that no one takes you captive by philosophy and empty deceit, according to human tradition, according to the elemental spirits of the world, and not according to Christ" (Colossians 2:8). Instead of allowing false teachings, deceptive philosophies, human traditions, and worldly spiritual forces to take our minds and hearts captive, we are to "destroy arguments and every lofty opinion raised against the knowledge of God, and take every thought captive to obey Christ" (2 Corinthians 10:5).

The "peace" of Colossians 3:15 is a tranquility that results from a proper recognition of salvation's worth. Jesus Christ obtained the ultimate peace for us by taking away the hostility between God and us through His atoning sacrifice on the cross to pardon our sin, as demonstrated by His resurrection. We let the peace of Christ rule in our hearts by taking every anxious thought and turning it into a prayer. Paul told the Romans, "If possible, so far as it depends on you, live peaceably with all" (Romans 12:18). Hebrews 12:14 cautions, "Strive for peace with everyone, and for the holiness without which no one will see the Lord."

God's peace is a tremendous blessing (Numbers 6:24–26). It is an umpire to rule in our hearts, a guardian to keep watch over our minds, an exceedingly precious gift from our Savior, a necessary virtue for living in unity with other believers, and a keepsake of God's constant presence to care for us throughout this life.