You have heard that it was said, ‘An eye for an eye and a tooth for a tooth.’ But I say to you, Do not resist an evildoer. But if anyone strikes you on the right cheek, turn the other also …” (Mt 5:38–39). To understand this text correctly, we must keep in mind that the Old Testament principle “an eye for an eye, a tooth for a tooth” (Ex 21:24; Lev 24:20; Dt 19:21) is far from being a canonization of vengeance; on the contrary, its purpose is to substitute the principle of justice for the principle of vengeance.… Justice must be safeguarded; but its safeguarding must not degenerate into vengeance.… Jesus does not reject the principle of equality as a legal norm, but his purpose here is to open to men a new dimension of his own character. An absolute and rigid justice becomes a circulus vitiosus, a cycle of retaliations from which there is no escape. In his dealings with us, God has broken through this circle. We are unjust before God; we have turned away from him in pursuit of our own glorification and so we have become subject to death. But God waives the merited punishment and puts something new in its place: healing; our conversion to a renewed Yes to the truth about ourselves. So that this transformation may take place, he goes before us and takes upon himself the pain of our transformation. The Cross of Christ is the real elucidation of these words: not “an eye for an eye, a tooth for a tooth”, but “transform evil by the power of love.…” In the Cross of Christ, and only there, these words open themselves to us and become revelation. In the company of the Cross, they become a new possibility even for our own lives.
Ratzinger, J. (1992). Co-Workers of the Truth: Meditations for Every Day of the Year. (M. F. McCarthy & L. Krauth, Trans., I. Grassl, Ed.) (pp. 78–79). San Francisco: Ignatius Press.