Before being God's gift to man and a human project in conformity with the divine plan, peace is in the first place a basic attribute of God: “the Lord is peace” (Jdg 6:24). Creation, which is a reflection of the divine glory, aspires to peace. God created all that exists, and all of creation forms a harmonious whole that is good in its every part (cf. Gen 1:4,10,18,21,25,31). Peace is founded on the primary relationship that exists between every human being and God himself, a relationship marked by righteousness (cf. Gen 17:1). Following upon the voluntary act by which man altered the divine order, the world experienced the shedding of blood and division. Violence made its appearance in interpersonal relationships (cf. Gen 4:1-16) and in social relationships (cf. Gen 11:1-9). Peace and violence cannot dwell together, and where there is violence, God cannot be present (cf. 1 Chr 22:8-9).
In biblical revelation, peace is much more than the simple absence of war; it represents the fullness of life (cf. Mal 2:5). Far from being the work of human hands, it is one of the greatest gifts that God offers to all men and women, and it involves obedience to the divine plan. Peace is the effect of the blessing that God bestows upon his people: “The Lord lift up his countenance upon you, and give you peace” (Num 6:26). This peace produces fruitfulness (Is 48:19), well-being (cf. Is 48:18), prosperity (cf. Is 54:13), absence of fear (cf. Lev 26:6) and profound joy (cf. Pr 12:20).
Peace is the goal of life in society, as is made extraordinarily clear in the messianic vision of peace: when all peoples will go up to the Lord's house, and he will teach them his ways and they will walk along the ways of peace (cf. Is 2:2-5). A new world of peace that embraces all of nature is the promise of the messianic age (cf. Is 11:6-9), and the Messiah himself is called “Prince of peace” (Is 9:5). Wherever his peace reigns, wherever it is present even in part, no longer will anyone be able to make the people of God fearful (cf. Zeph 3:13). It is then that peace will be lasting, because when the king rules according to God's justice, righteousness flourishes and peace abounds “till the moon be no more” (Ps 72:7). God longs to give peace to his people: “he will speak of peace to his people, to his saints, to those who turn to him in their hearts” (Ps 85:9). Listening to what God has to say to his people about peace, the Psalmist hears these words: “Steadfast love and faithfulness will meet; righteousness and peace will kiss” (Ps 85:11).
The promise of peace that runs through the entire Old Testament finds its fulfilment in the very person of Jesus. Peace, in fact, is the messianic attribute par excellence, in which all other beneficial effects of salvation are included. The Hebrew word “shalom” expresses this fullness of meaning in its etymological sense of “completeness” (cf. Is 9:5ff; Mic 5:1-4). The kingdom of the Messiah is precisely the kingdom of peace (cf. Job 25:2; Ps 29:11; 37:11; 72:3,7; 85:9,11; 119:165; 125:5, 128:6; 147:14; Song 8:10; Is 26:3,12; 32:17f.; 52:7; 54:10; 57:19; 60:17; 66:12; Hag 2:9; Zech 9:10; et al.). Jesus “is our peace” (Eph 2:14). He has broken down the dividing wall of hostility among people, reconciling them with God (cf. Eph 2:14-16). This is the very effective simplicity with which Saint Paul indicates the radical motivation spurring Christians to undertake a life and a mission of peace. On the eve of his death, Jesus speaks of his loving relation with the Father and the unifying power that this love bestows upon his disciples. It is a farewell discourse which reveals the profound meaning of his life and can be considered a summary of all his teaching. The gift of peace is the seal on his spiritual testament: “Peace I leave with you; my peace I give to you; not as the world gives do I give to you” (Jn 14:27). The words of the Risen Lord will not be any different; every time that he meets his disciples they receive from him the greeting and gift of peace: “Peace be with you” (Lk 24:36; Jn 20:19,21,26).
The peace of Christ is in the first place reconciliation with the Father, which is brought about by the ministry Jesus entrusted to his disciples and which begins with the proclamation of peace: “Whatever house you enter, first say, ‘Peace be to this house!”' (Lk 10:5; cf. Rom 1:7). Peace is then reconciliation with one's brothers and sisters, for in the prayer that Jesus taught us, the “Our Father”, the forgiveness that we ask of God is linked to the forgiveness that we grant to our brothers and sisters: “Forgive us our debts as we also have forgiven our debtors” (Mt 6:12). With this twofold reconciliation Christians can become peacemakers and therefore participate in the Kingdom of God, in accordance with what Jesus himself proclaims in the Beatitudes: “Blessed are the peacemakers, for they shall be called children of God” (Mt 5:9).
Working for peace can never be separated from announcing the Gospel, which is in fact the “good news of peace” (Acts 10:36; cf. Eph 6:15) addressed to all men and women. At the centre of “the gospel of peace” (Eph 6:15) remains the mystery of the cross, because peace is born of Christ's sacrifice (cf. Is 53:5) — “Upon him was the chastisement that made us whole, and with his stripes we were healed”. The crucified Jesus has overcome divisions, re-establishing peace and reconciliation, precisely through the cross, “thereby bringing the hostility to an end” (Eph 2:16) and bringing the salvation of the Resurrection to mankind.