What does God require in the sixth commandment?

Heidelberg Catechism (extended)

The Catechism
Method of Instruction in the Christian Religion
As the Same is Taught in the Reformed Churches and Schools

(with the Scripture references written out)

Note. This Catechism is fully based on the Scriptures. The references to Scripture are indicated in parentheses with a letter. For example, the letter (a) points to the texts (a) placed after the answer.

40. Lord's Day 

 Q. 105. What does God require in the sixth commandment? 

A. That neither in thoughts, nor words, nor gestures, much less in deeds, I dishonour, hate, wound, or kill my neighbour, by myself or by another: (a) but that I lay aside all desire of revenge: (b) also, that I hurt not myself, nor wilfully expose myself to any danger. (c) Wherefore also the magistrate is armed with the sword, to prevent murder. (d) 

 (a) Matt.5:21 Ye have heard that it was said by them of old time, Thou shalt not kill; and whosoever shall kill shall be in danger of the judgment: Matt.5:22 But I say unto you, That whosoever is angry with his brother without a cause shall be in danger of the judgment: and whosoever shall say to his brother, Raca, shall be in danger of the council: but whosoever shall say, Thou fool, shall be in danger of hell fire. Matt.26:52 Then said Jesus unto him, Put up again thy sword into his place: for all they that take the sword shall perish with the sword. Gen.9:6 Whoso sheddeth man's blood, by man shall his blood be shed: for in the image of God made he man. 

(b) Eph.4:26 Be ye angry, and sin not: let not the sun go down upon your wrath: Rom.12:19 Dearly beloved, avenge not yourselves, but rather give place unto wrath: for it is written, Vengeance is mine; I will repay, saith the Lord. Matt.5:25 Agree with thine adversary quickly, whiles thou art in the way with him; lest at any time the adversary deliver thee to the judge, and the judge deliver thee to the officer, and thou be cast into prison. Matt.18:35 So likewise shall my heavenly Father do also unto you, if ye from your hearts forgive not every one his brother their trespasses. 

(c) Rom.13:14 But put ye on the Lord Jesus Christ, and make not provision for the flesh, to fulfil the lusts thereof. Col.2:23 Which things have indeed a shew of wisdom in will worship, and humility, and neglecting of the body; not in any honour to the satisfying of the flesh. Matt.4:7 Jesus said unto him, It is written again, Thou shalt not tempt the Lord thy God. 

(d) Gen.9:6 Whoso sheddeth man's blood, by man shall his blood be shed: for in the image of God made he man. Exod.21:14 But if a man come presumptuously upon his neighbour, to slay him with guile; thou shalt take him from mine altar, that he may die. Matt.26:52 Then said Jesus unto him, Put up again thy sword into his place: for all they that take the sword shall perish with the sword. Rom.13:4 For he is the minister of God to thee for good. But if thou do that which is evil, be afraid; for he beareth not the sword in vain: for he is the minister of God, a revenger to execute wrath upon him that doeth evil. 

 Q. 106. But this commandment seems only to speak of murder? 

A. In forbidding murder, God teaches us, that he abhors the causes thereof, such as envy, (a) hatred, (b) anger, (c) and desire of revenge; and that he accounts all these as murder. (d) 

 (a) Prov.14:30 A sound heart is the life of the flesh: but envy the rottenness of the bones. Rom.1:29 Being filled with all unrighteousness, fornication, wickedness, covetousness, maliciousness; full of envy, murder, debate, deceit, malignity; whisperers, 

(b) 1 John 2:9 He that saith he is in the light, and hateth his brother, is in darkness even until now. 1 John 2:11 But he that hateth his brother is in darkness, and walketh in darkness, and knoweth not whither he goeth, because that darkness hath blinded his eyes. 

(c) James 1:20 For the wrath of man worketh not the righteousness of God. Gal.5:19 Now the works of the flesh are manifest, which are these; Adultery, fornication, uncleanness, lasciviousness, Gal.5:20 Idolatry, witchcraft, hatred, variance, emulations, wrath, strife, seditions, heresies, Gal.5:21 Envyings, murders, drunkenness, revellings, and such like: of the which I tell you before, as I have also told you in time past, that they which do such things shall not inherit the kingdom of God. 

(d) 1 John 3:15 Whosoever hateth his brother is a murderer: and ye know that no murderer hath eternal life abiding in him. 

 Q. 107. But is it enough that we do not kill any man in the manner mentioned above? 

A. No: for when God forbids envy, hatred, and anger, he commands us to love our neighbour as ourselves; (a) to show patience, peace, meekness, mercy, and all kindness, towards him, (b) and prevent his hurt as much as in us lies; (c) and that we do good, even to our enemies. (d) 

 (a) Matt.7:12 Therefore all things whatsoever ye would that men should do to you, do ye even so to them: for this is the law and the prophets. Matt.22:39 And the second is like unto it, Thou shalt love thy neighbour as thyself. Rom.12:10 Be kindly affectioned one to another with brotherly love; in honour preferring one another; 

(b) Eph.4:2 With all lowliness and meekness, with longsuffering, forbearing one another in love; Gal.6:1 Brethren, if a man be overtaken in a fault, ye which are spiritual, restore such an one in the spirit of meekness; considering thyself, lest thou also be tempted. Gal.6:2 Bear ye one another's burdens, and so fulfil the law of Christ. Matt.5:5 Blessed are the meek: for they shall inherit the earth. Matt.5:7 Blessed are the merciful: for they shall obtain mercy. Matt.5:9 Blessed are the peacemakers: for they shall be called the children of God. Rom.12:18 If it be possible, as much as lieth in you, live peaceably with all men. Luke 6:36 Be ye therefore merciful, as your Father also is merciful. 1 Pet.3:8 Finally, be ye all of one mind, having compassion one of another, love as brethren, be pitiful, be courteous: Col.3:12 Put on therefore, as the elect of God, holy and beloved, bowels of mercies, kindness, humbleness of mind, meekness, longsuffering; Rom.12:10 Be kindly affectioned one to another with brotherly love; in honour preferring one another; Rom.12:15 Rejoice with them that do rejoice, and weep with them that weep. 

(c) Exod.23:5 If thou see the ass of him that hateth thee lying under his burden, and wouldest forbear to help him, thou shalt surely help with him. 

(d) Matt.5:44 But I say unto you, Love your enemies, bless them that curse you, do good to them that hate you, and pray for them which despitefully use you, and persecute you; Matt.5:45 That ye may be the children of your Father which is in heaven: for he maketh his sun to rise on the evil and on the good, and sendeth rain on the just and on the unjust. Rom.12:20 Therefore if thine enemy hunger, feed him; if he thirst, give him drink: for in so doing thou shalt heap coals of fire on his head. Rom.12:21 Be not overcome of evil, but overcome evil with good.

Source: http://www.ccel.org/creeds/heidelberg-cat-ext.txt