Reconciliation
Reconciliation (Greek katallagē) is the restoration of a broken relationship — the change from enmity to peace between God and sinners through the work of Christ. Scripture is candid that the breach is real: apart from Christ we were "enemies" of God, "alienated and hostile in mind" (Romans 5:10; Colossians 1:21).
The initiative is entirely God’s — he is the reconciler, not the one who needs to be appeased into it: "God was in Christ reconciling the world to himself, not counting their trespasses against them" (2 Corinthians 5:18–19). The means is the death of his Son: "while we were enemies we were reconciled to God by the death of his Son" (Romans 5:10). The result is peace with God and standing access into his grace, so that we now rejoice in him (Romans 5:1–2; Romans 5:11).
Its scope is cosmic: through Christ God was pleased "to reconcile to himself all things… whether on earth or in heaven, making peace by the blood of his cross" (Colossians 1:20). And it has a horizontal dimension that flows from the vertical: in Christ the dividing wall between Jew and Gentile is broken down, "that he might… reconcile us both to God in one body through the cross" (Ephesians 2:14–16) — so reconciliation with God compels reconciliation with one another (Matthew 5:23–24).
This reconciled people is then given the "ministry of reconciliation": "we are ambassadors for Christ, God making his appeal through us… be reconciled to God" (2 Corinthians 5:20). At the heart of the gospel is a God who, at the cost of his own Son, turns enemies into beloved children at peace with him.