What does Matthew 5:9 mean?

Next in Matthew's record of "the Beatitudes"—a series of statements about godly attitudes and benefits—is a reference to "peacemakers." Jesus declares that peacemakers are blessed: they have received a good thing, because they will be called sons of God. This is an early part of the Sermon on the Mount (Matthew 5:1–2).

The commitment to make peace is highly valued throughout the Bible, but what does it mean to be a peacemaker? Biblically, a peacemaker is someone who reconciles people who were formerly in conflict. The heart of Jesus' earthly mission was to make peace between God and those who would come to Him through faith. This is eloquently expressed by Paul in his letter to the church at Ephesus:

"For he himself is our peace, who has made us both one and has broken down in his flesh the dividing wall of hostility by abolishing the law of commandments expressed in ordinances, that he might create in himself one new man in place of the two, so making peace, and might reconcile us both to God in one body through the cross, thereby killing the hostility. And he came and preached peace to you who were far off and peace to those who were near" (Ephesians 2:14–17).

Christ made this peace "by the blood of his cross" (Colossians 1:20). In other words, His death in our place on the cross paid for our sins. It removed the barrier between humanity and God. Everyone who comes to God through Christ and the cross finds they have peace with God (Romans 5:1).

It makes sense, then, that everyone who commits to making peace between others, especially by their own sacrifice, imitates what Christ has done. Such a person is called a "son of God" similarly to how Israel was called God's son in the Old Testament (Exodus 4:22).