“Be ye all of one mind … not rendering evil for evil.”
The Gospel today refers us to the Fifth Commandment; “Thou shalt not kill.” Perhaps more accurately, it is translated, “Thou shalt not murder,” because what it is dealing with is the unjust taking of life. It tells us that we must not take the life of someone who has done us no serious harm. “The innocent and just person thou shalt not put to death: because I abhor the wicked.”
It forbids direct murder of another, the abortion of a baby, or taking our own life in suicide. The issue here is an unjust taking of life, so we are not restrained from using violence in self defense or in defense of another. And a properly constituted government is not restrained from treating criminals with violence in just punishment for their misdeeds.
The Commandment also forbids those kinds of carelessness that might lead to our own death or the death of another. Drunken driving, shoddy construction, reckless use of a fire arm . . . all these things might lead to the death or injury of another. Excessive eating or drinking, dangerous pastimes, or just simply neglecting our own health . . . may lead to our own demise.
Obviously there are limits to the caution God expects of us. Driving a car, for example, always constitutes some amount of risk, but a sober and prudent person is justified in taking that risk as long as he follows the accepted precautions. Likewise, we are required to take care of ourselves, but we are not expected to undergo very painful, expensive, or experimental treatment when we are ill—nor are we required to undergo unusual treatments that will preserve us in a worse state than we are already in.
The Fifth Commandment also prohibits us from fighting with another; either physically or even just with heated language. It obviously does not exclude taking part in physical sports, but does require us to take precautions against seriously injuring ourselves or our opponents.
We are urged not even to hate another, for that hate often turns into greater and greater animosity and even physical violence.
But if we examine what our Lord has to say in this Gospel, or what Saint Peter had to say in his Epistle, we see that the Commandment is a bare minimum. We are not to get angry, or even to insult another. We are expected to be “merciful, modest, and humble…. blessing those who curse us.” We are to “suffer persecution for justice' sake.”
Certainly, we are expected to show this kind of kindness and compassion for one another—the members of our family, for our fellow Christians, for our neighbors. Saint Peter speaks of being “lovers of the brotherhood.” Our Lord reminds us of the duty to “be reconciled with our brother.” So, clearly there is a duty to be good to those with whom we have a close relationship.
But it doesn't take too much imagination to see that we ought to have a similar outlook, even toward those who are not close to us—even toward those who are quite different from us. We are all made in God's “Image and likeness,” and we ought to have respect for that in everyone with whom we deal.
We are reminded of the example set by our Lord Himself, never allowing Himself to be unkind with others—even to the point of humbly accepting His violent death on the Cross.
Perhaps even more strongly, we are reminded that unless our justice is greater than that of the Scribes and the Pharisees, we will not enter into the kingdom of heaven.
 Epistle: I Peter iii:8-15 http://www.drbo.org/cgi-bin/d?b=drblbk=67&ch=3&l=8-#x
 Exodus xxiii:7 http://www.drbo.org/cgi-bin/d?b=drl&bk=2&ch=23&l=7-#x
 Summa Theol II-II Q. 64 http://www.newadvent.org/summa/3064.htm
 Genesis ix: 6 http://www.drbo.org/cgi-bin/d?b=drl&bk=1&ch=9&l=6-#x,
Exodus xxii; 18-20 http://www.drbo.org/cgi-bin/d?b=drl&bk=2&ch=22&l=18-#x,
Romans xiii: 4 http://www.drbo.org/cgi-bin/d?b=drl&bk=52&ch=13&l=4-#x
 I Peter iii:8 http://www.drbo.org/cgi-bin/d?b=drl&bk=67&ch=3&l=8#x
Luke vi:28 http://www.drbo.org/cgi-bin/d?b=drl&bk=49&ch=6&l=28#x
 Matthew v:10 http://www.drbo.org/cgi-bin/d?b=drl&bk=47&ch=5&l=10#x