What does it mean that 'blessed are the peacemakers'?

TL;DR:

A peacemaker actively works toward peace. Peacemakers will find joy in the experience of seeing people reconciled to one another and to God.

In the Sermon on the Mount, Jesus opens with a series of statements concerning blessedness known as the Beatitudes. The seventh Beatitude is "Blessed are the peacemakers, for they shall be called sons of God" (Matthew 5:9). The Greek word translated "blessed" in this verse is one that is also translated "happy." A blessed person will have joy and contentment. Also, we must understand what a "peacemaker" is. The Greek word simply indicates a person who makes or works toward peace. A person can only work toward peace if he is at peace himself. Believers have peace with God through Jesus Christ (Romans 5:1). God is the source of peace (Philippians 4:7) and calls His followers to exhibit peace in their own lives (Romans 12:18; Galatians 5:22).

from the old testament

Jesus Himself is called the "Prince of Peace" in Isaiah 9:6. Living as a peacemaker follows His example; He provided peace with God through His sacrificial death on the cross.
King Solomon wisely realized the blessings of having a peaceful heart: “Deceit is in the heart of those who devise evil, but those who plan peace have joy” (Proverbs 12:20).
Solomon also knew that inward peace would flow out of our hearts towards others: “When a man's ways please the LORD, he makes even his enemies to be at peace with him” (Proverbs 16:7).

from the new testament

Ephesians 2:14–16 reveals that Jesus is our peace since He reconciled Jew and Gentile both to God and to each other.
Jesus offers this same peace to His followers: "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 said that peacemakers are blessed because they will be called sons of God. In other words, they will have the honor of being identified as children of "the God of peace" (Romans 15:33).
To live as a child of God is to have the greatest relationship in the world. It's a relationship made possible by the Prince of Peace: "for in Christ Jesus you are all sons of God, through faith" (Galatians 3:26).

implications for today

A peacemaker actively works toward peace. Whether it's to provide peace between two people or two nations, our world is in much need of those who represent the heart of God to bring peace to broken relationships. Those who assist in such efforts will find joy in the experience of seeing people reconciled to one another and to God. Every believer should be a peacemaker in the sense of spreading the good news that peace with God is possible. "Peace" was part of the angels' message to the shepherds when Jesus was born (Luke 2:14). "Peace" is part of our message to the world because God "through Christ reconciled us to himself and gave us the ministry of reconciliation" (2 Corinthians 5:18).

Only children of God can bring the peace of knowing God to others. A person must have a real relationship with God before he or she can help someone else know God. Those who witness for Christ, share their faith with their friends, and serve others in the name of Christ are ambassadors for peace (Matthew 5:9; 10:41–42). Those who bring the wonderful message of God’s peace to the world are "peacemakers," and Jesus calls them the "children of God."

understand

Peacemakers have peace with God through Jesus, enabling them to promote peace in their relationships.
Peacemakers mirror God's nature and are called "sons of God" because they actively work towards reconciliation and harmony.
Blessed are the peacemakers because they engage in reconciling others to God and each other.

reflect

In what areas of your life are you actively working toward peace? Where might you need to be more intentional about being a peacemaker?
How can experiencing God’s peace through Jesus influence the way you handle conflicts and disagreements in your relationships?
What steps can you take to reflect the heart of God by being a peacemaker in your community or family?

engage

How is being a peacemaker countercultural in society today?
How can believers demonstrate the peace of God in a world filled with division and hostility?
How can understanding Jesus as the "Prince of Peace" shape our approach to addressing issues of injustice and reconciliation today?