"Thou shalt not kill."

The duties required of the sixth commandment are,
-all careful studies, and lawful endeavors, to preserve the life of ourselves and others, by resisting all thoughts and purposes, subduing all passions, and avoiding all occasions, temptations, and practices, which tend to the unjust taking away the life of any;
- by just defense thereof against violence;
- patient bearing of the hand of God, quietness of mind, cheerfulness of spirit;
-a sober use of meat, drink, physic, sleep, labor, and recreation;
-by charitable thoughts, love, compassion, meekness, gentleness, kindness;
-peaceable, mild; and courteous speeches and behavior;
forbearing, readiness to be reconciled, patient bearing and forgiving of injuries, and requiting good for evil:
-comforting and succoring the distressed, and protecting and defending the innocent. (taken from the Larger Catechism of the Presbyterian Church - Answer to Question 135)

Commanded: Loving others, with reverence for all human life, preserving it (with the few exceptions authorized by God); maintaining a patient, forgiving love, and cultivating gentle, compassionate, humble attitudes in yourself and others; striving to promote the bodily and spiritual well-being of others as well as self.

"Now the Scripture states two reasons on which this precept is founded; the first, that man is the image of God; the second, that he is our own flesh.  Wherefore, unless we would violate the image of God, we ought to hold the personal safety of our neighbor inviolably sacred; and unless we would divest ourselves of humanity, we ought to cherish him as our own flesh."  (taken from Calvin's Institutes, II, 8, 40)

The sins forbidden in the sixth commandment are,
-all taking away the life of ourselves, or of others, Except in case of public justice, lawful war, or necessary defense
-the neglecting or withdrawing the lawful or necessary means of preservation of life;
-sinful anger, hatred, envy, desire of revenge
(taken from the Larger Catechism of the Presbyterian Church - Answer to Question 136).

Forbidden: Unrighteous, prideful anger; hatred, resentments, envy; excessive self-indulging, immoderate living, vexing cares, or anything that would tend to bring bodily or spiritual harm or death to others, as well as to yourself.