Matthew 5:9, “Blessed are the peacemakers, for they shall be called sons of God.”
If we are to use one word to describe what the gospel brings to people when they repent and believe, that one word would be salvation. God’s people are saved from the wrath of God when they put their face in Christ alone (1 Thessalonians 1:9-10). Even so, we could answer this question another way (and truthfully many other ways) and that is by answering it with the word peace. Paul refers to the gospel as the “gospel of peace” (Ephesians 6:15). He also tells us that having been justified by faith alone in Christ alone, Christians have “peace with God through our Lord Jesus Christ” (Romans 5:1).
Unregenerate people are alienated from God, and this alienation from the Creator is the lot of all of Adam’s natural born descendants before they know the Lord Jesus. All of humanity are born into sin (Romans 5:12-21) and are not only alienated from God but at war with him until they trust in Christ alone for salvation. Apart from Jesus, we are slaves to sin and under condemnation justly deserving of the wrath of God (Romans 1:18-32; James 4:4). The good news is that the God-Man the Lord Jesus is the mediator between God and man (John 1:1, 14; 1 Timothy 2:5). Jesus is the “mediator of a new covenant” who guarantees the inheritance to all those who believe in Christ alone (Hebrews 9:11-28). Fully human (and fully God) Jesus alone is able to represent the people of God before God the Father. Only through Christ alone are Christians declared righteous before God. By being fully God (and fully human), the Lord Jesus represents God the Father as the One sent to reveal the wrath of God against the sins of His people and also to display the love of God in giving His Son Jesus to die in the place of His people.
You and I cannot be mediators in relation to redeeming others from the sin. Instead, we can imitate our Creator’s work of peacemaking through Christ by helping bring about real and godly peace between warring parties by proclaiming the gospel message and by doing so give evidence that we are children of God (Matthew 5:9).
Peacemaking reveals the status of God’s children as it relates to authentic, holy peace. The false prophets of Israel preached a fake, ungodly peace. As Christians, we proclaim peace because we know the Lord Jesus and know the difference between biblical and false peace, which is why as Christians we proclaim the gospel of peace and make clear that only in Christ alone is there hope and salvation for sinners at war with God.