What is peace?
Peace is the consequence of justice and the sign of love put into action. Where there is peace, "every creature can come to rest in good order" (Thomas Aquinas). Earthly peace is the image of the peace of Christ, who reconciled heaven and earth. Peace is more than the absence of war, more than a carefully maintained balance of powers ("balance of terror"). In a state of peace, people can live securely with their legitimately earned property and freely exchange goods with one another. In peace the dignity and the right of self-determination of individuals and of peoples are respected. In peace human coexistence is characterized by brotherly solidarity.
How does a Christian deal with anger?
Paul says, "Be angry but do not sin; do not let the sun go down on your anger" (Eph 4:26). Anger is initially a natural emotion, a reaction to perceived injustice. If anger becomes hatred, however, and someone has ill-will toward his neighbor, this normal feeling becomes a serious offense against charity. All uncontrolled anger, especially thoughts of revenge, are detrimental to peace and destroy "the tranquility of order".
What does Jesus think about nonviolence?
Jesus places a high value on nonviolent action. He commands his disciples: "Do not resist one who is evil. But if any one strikes you on the right cheek, turn to him the other also" (Mt 5:39). He rebukes Peter, who wants to defend him with force: "Put your sword into its sheath" (Jn 18:11). Jesus does not call his disciples to take up weapons. He remains silent before Pilate. His way is to take the part of the victims, to go to the Cross, to redeem the world through love, and to call the peacemakers blessed. Therefore the Church, too, respects people who for reasons of conscience refuse to be part of the armed services but place themselves at the service of society in some other way.
Must Christians be pacifists?
The Church strives for peace but does not preach radical pacifism. Indeed, no one can deny either the individual citizen or particular governments and alliances the fundamental right of armed self-defence. War is morally justifiable only as a last resort. The Church unmistakably says No to war. Christians should do everything possible to avoid war before it starts: They oppose the stockpiling of arms and trafficking in weapons; they fight against racial, ethnic, and religious discrimination; they work to put an end to economic and social injustice and thus promote peace.
(From the Catholic Youth Catechism)