Love your enemies
Jesus said to his disciples: “To you who hear I say, love your enemies, do good to those who hate you, bless those who curse you, pray for those who mistreat you. To the person who strikes you on one cheek, offer the other one as well, and from the person who takes your cloak, do not withhold even your tunic. Give to everyone who asks of you, and from the one who takes what is yours do not demand it back. Do to others as you would have them do to you. For if you love those who love you, what credit is that to you? Even sinners love those who love them. And if you do good to those who do good to you, what credit is that to you? Even sinners do the same. If you lend money to those from whom you expect repayment, what credit is that to you? Even sinners lend to sinners, and get back the same amount. But rather, love your enemies and do good to them, and lend expecting nothing back; then your reward will be great and you will be children of the Most High, for he himself is kind to the ungrateful and the wicked. Be merciful, just as [also] your Father is merciful. (Luke 6:27-36)
The Gospel passage above is part of the Sermon on the Plain in the Gospel according to Luke. Jesus tells His disciples to love their enemies and to turn the other cheek. Jesus practiced what He preached during His arrest at the Garden of Gethsemane; He did not defend himself and told Peter to leave his sword in its sheath (cf. Mt 26:47-52). Neither did Jesus retaliate when He was spit on and struck on the face by the chief priests (cf. Matthew 26:67-68).
Does this mean that we should not defend ourselves at all times? Definitely not. According to the Catechism, love toward oneself remains a fundamental principle of morality. Therefore, it is legitimate to insist on one’s own right to life. Someone who defends his life is not guilty of murder even if he is forced to deal his aggressor a lethal blow. In addition, legitimate defense is not only a right but a grave duty for one who is responsible for the lives of others. The defense of the common good requires that an unjust aggressor be rendered unable to cause harm. (CCC 2264-2265)
Some people feel that if someone offended them, then they should do the same to that person. That is called revenge, and Jesus clearly teaches us not to do that. The Catechism tells us that it is illicit to desire vengeance in order to do evil to someone who should be punished; but on the other hand, to impose restitution to correct vices and maintain justice is praiseworthy. Moreover, if anger reaches the point of deliberately desiring to kill or seriously wound another, it is a mortal sin against charity. (CCC 2302)
The main point of “turning the other cheek” is not about not defending oneself; but that as followers of Christ, we should forgive and love our enemies, just as we forgive and love our friends and those who do good things to us. In the same way that God lets both the just and unjust receive the goodness of His gifts to mankind, so too should we should treat everyone the same when it comes to love and forgiveness. Jesus tells us to do good even to our enemies, for then our reward will be great in heaven; we will be children of the Most-High God because we are merciful, just as our Father in heaven is merciful.