The Heidelberg Catechism: Lord's Day 43

112. Question: What is required in the ninth commandment?

 Answer: I must not give false testimony against anyone, twist no one’s words,  not gossip or slander, nor condemn or join in condemning anyone rashly and  unheard.[1] Rather, I must avoid all lying and deceit as the devil’s own works,
under penalty of God’s heavy wrath.[2] In court and everywhere else, I must love
the truth,[3] speak and confess it honestly, and do what I can to defend and promote my neighbor’s honor and reputation.[4]

 [1] Ps. 15; Prov. 19:5, 9; 21:28; Matt. 7:1; Luke 6:37; Rom. 1:28-32. [2] Lev. 19:11, 12; Prov. 12:22; 13:5; John 8:44; Rev. 21:8. [3] I Cor. 13:6; Eph. 4:25. [4] I Pet. 3:8, 9; 4:8.

The Heidelberg Catechism: Lord's Day 42

110. Question: What does God forbid in the eighth commandment?

 Answer: God forbids not only outright theft and robbery[1] but also such wicked schemes and devices as false weights and measures, deceptive merchandising, counterfeit money, and usury;[2] we must not defraud our neighbor in any way, whether by force or by show of right.[3] In addition God forbids all greed[4] and all abuse or squandering of His gifts.[5]

 [1] Ex. 22:1; I Cor. 5:9, 10; 6:9, 10. [2] Deut. 25:13-16; Ps. 15:5; Prov. 11:1; 12:22; Ezek. 45:9-12; Luke 6:35. [3] Mic. 6:9-11; Luke 3:14; James 5:1-6. [4] Luke 12:15; Eph. 5:5. [5] Prov. 21:20; 23:20, 21; Luke 16:10-13.

 111. Question: What does God require of you in this commandment?

 Answer: I must promote my neighbor’s good wherever I can and may, deal with him as I would like others to deal with me, and work faithfully so that I may be able to give to those in need.[1]

 [1] Is. 58:5-10; Matt. 7:12; Gal. 6:9, 10; Eph. 4:28.

The Heidelberg Catechism: Lord's Day 41

108. Question: What does the seventh commandment teach us?

 Answer: That all unchastity is cursed by God.[1] We must therefore detest it from the heart[2] and live chaste and disciplined lives, both within and outside of holy marriage.[3]

 [1] Lev. 18:30; Eph. 5:3-5. [2] Jude 22, 23. [3] I Cor. 7:1-9; I Thess. 4:3-8; Heb. 13:4.

 109. Question: Does God in this commandment forbid nothing more than adultery and similar shameful sins?

 Answer: Since we, body and soul, are temples of the Holy Spirit, it is God’s will that we keep ourselves pure and holy. Therefore He forbids all unchaste acts, gestures, words, thoughts, desires,[1] and whatever may entice us to
unchastity.[2]

 [1] Matt. 5:27-29; I Cor. 6:18-20; Eph. 5:3, 4. [2] I Cor. 15:33; Eph. 5:18.

The Heidelberg Catechism: Lord's Day 40

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

A. I am not to dishonor, hate, injure, or kill my neighbor by thoughts, words, or gestures, and much less by deeds, whether personally or through another;[1] rather, I am to put away all desire of revenge.[2] Moreover, I am not to harm or recklessly endanger myself.[3] Therefore, also, the government bears the sword to prevent murder.[4]

[1] Gen. 9:6; Lev. 19:17, 18; Matt. 5:21, 22; 26:52. [2] Prov. 25:21, 22; Matt. 18:35; Rom. 12:19; Eph. 4:26. [3] Matt. 4:7; 26:52; Rom. 13:11-14. [4] Gen. 9:6; Ex. 21:14; Rom. 13:4.

106. Q. But does this commandment speak only of killing?

A. By forbidding murder God teaches us that He hates the root of murder, such as envy, hatred, anger, and desire of revenge,[1] and that He regards all these as murder.[2]

[1] Prov. 14:30; Rom. 1:29; 12:19; Gal. 5:19-21; James 1:20; I John 2:9-11. [2] I John 3:15.

107. Q. Is it enough, then, that we do not kill our neighbor in any such way?

A. No. When God condemns envy, hatred, and anger, He commands us to love our neighbor as ourselves,[1] to show patience, peace, gentleness, mercy, and friendliness toward him,[2] to protect him from harm as much as we can, and to do good even to our enemies.[3]

[1] Matt. 7:12; 22:39; Rom. 12:10. [2] Matt. 5:5; Luke 6:36; Rom. 12:10, 18; Gal. 6:1, 2; Eph. 4:2; Col. 3:12; I Pet. 3:8. [3] Ex. 23:4, 5; Matt. 5:44, 45; Rom. 12:20.

The Heidelberg Catechism: Lord's Day 39

Question 104: What is God's will for you in the fifth commandment?

Answer: That I honor, love, and be loyal to my father and mother and all those in authority over me; that I obey and submit to them, as is proper, when they correct and punish me; [1] and also that I be patient with their failings - [2] for through them God chooses to rule us. [3]

[1] Ex. 21:17; Prov. 1:8; 4:1; Rom. 13:1-2; Eph. 5:21-22; 6:1-9; Col. 3:18-4:1; [2] Prov. 20:20; 23:22; 1 Pet. 2:18; [3] Matt. 22:21; Rom. 13:1-8; Eph. 6:1-9; Col. 3:18-21

The Heidelberg Catechism: Lord's Day 37

101. Question: But may we swear an oath by the Name of God in a godly
manner?

Answer: Yes, when the government demands it of its subjects, or when necessity requires it, in order to maintain and promote fidelity and truth, to God's glory and for our neighbor’s good. Such oath-taking is based on God's
Word[1] and was therefore rightly used by saints in the Old and the New Testament.[2]

[1] Deut. 6:13; 10:20; Jer. 4:1, 2; Heb. 6:16. [2] Gen. 21:24; 31:53; Josh. 9:15; I Sam. 24:22; I Kings 1:29, 30; Rom. 1:9; II Cor. 1:23.

102. Question: May we also swear by saints or other creatures?

Answer: No. A lawful oath is a calling upon God, who alone knows the heart, to bear witness to the truth, and to punish me if I swear falsely.[1] No creature is worthy of such honour.[2]

[1] Rom. 9:1; II Cor. 1:23. [2] Matt. 5:34-37; 23:16-22; James 5:12.

The Heidelberg Catechism: Lord's Day 36

99. Question: What is required in the third commandment?

 Answer: We are not to blaspheme or to abuse the Name of God by cursing,[1]
perjury,[2] or unnecessary oaths,[3] nor to share in such horrible sins by being
silent bystanders.[4] In short, we must use the holy Name of God only with fear
and reverence,[5] so that we may rightly confess Him,[6] call upon Him,[7] and praise Him in all our words and works.[8]

 [1] Lev. 24:10-17. [2] Lev. 19:12 [3] Matt. 5:37; James 5:12. [4] Lev. 5:1; Prov. 29:24. [5] Ps. 99:1-5; Is. 45:23; Jer. 4:2. [6] Matt. 10:32, 33; Rom. 10:9, 10. [7] Ps. 50:14, 15; I Tim. 2:8. [8] Rom. 2:24; Col. 3:17; I Tim. 6:1.

 100. Question: Is the blaspheming of God’s Name by swearing and cursing such a grievous sin that God is angry also with those who do not prevent and forbid it as much as they can?

 Answer: Certainly,[1] for no sin is greater or provokes God’s wrath more than the blaspheming of His Name. That is why He commanded it to be punished with death.[2]

 [1] Lev. 5:1. [2] Lev. 24:16.

The Heidelberg Catechism: Lord's Day 35

96. Question: What does God require in the second commandment?

 Answer: We are not to make an image of God in any way,[1] nor to worship Him in any other manner than He has commanded in His Word.[2]

 [1] Deut. 4:15-19; Is. 40:18-25; Acts 17:29; Rom. 1:23. [2] Lev. 10:1-7; Deut. 12:30; I Sam. 15:22, 23; Matt. 15:9; John 4:23, 24.

 97. Question: May we then not make any image at all?

 Answer: God cannot and may not be visibly portrayed in any way. Creatures may be portrayed, but God forbids us to make or have any images of them in order to worship them or to serve God through them.[1]

 [1] Ex. 34:13, 14, 17; Num. 33:52; II Kings 18:4, 5; Is. 40:25.

 98. Question: But may images not be tolerated in the churches as “books for the laity”?

 Answer: No, for we should not be wiser than God. He wants His people to be taught not by means of dumb images[1] but by the living preaching of His Word.[2]

 [1] Jer. 10:8; Hab. 2:18-20. [2] Rom. 10:14, 15, 17; II Tim. 3:16, 17; II Pet. 1:19.

The Heidelberg Catechism: Lord's Day 34

92. Question: What is the law of the LORD?

 Answer: God spoke all these words, saying: I am the LORD your God, who
brought you out of the land of Egypt, out of the house of bondage.

 1. You shall have no other gods before Me.

 2. You shall not make for yourself a graven image, or any likeness of anything that is in heaven above, or that is in the earth beneath, or that is in the water under the earth; you shall not bow down to them or serve them; for I
the LORD your God am a jealous God, visiting the iniquity of the fathers upon the children to the third and fourth generation of those who hate Me, but showing steadfast love to thousands of those who love Me and keep My
commandments.

 3. You shall not take the Name of the LORD your God in vain; for the LORD will not hold him guiltless who takes His Name in vain.

 4. Remember the sabbath day, to keep it holy. Six days you shall labor, and do all your work; but the seventh day is a sabbath to the LORD your God; in it you shall not do any work, you, or your son, or your daughter, your manservant, or your maidservant, or your cattle, or the sojourner who is within your gates; for in six days the LORD made heaven and earth, the sea, and all that is in them, and rested the seventh day; therefore the LORD blessed the sabbath day and hallowed it.

 5. Honour your father and your mother, that your days may be long in the land which the LORD your God gives you.

 6. You shall not kill.

 7. You shall not commit adultery.

 8. You shall not steal.

 9. You shall not bear false witness against your neighbor.

 10. you shall not covet your neighbor’s house; you shall not covet your neighbor’s wife, or his manservant, or his maidservant, 10. or his ox, or his ass, or anything that is your neighbor’s.[1]

 [1] Ex. 20:1-17; Deut. 5:6-21.

 93. Question: How are these commandments divided?

 Answer: Into two parts. The first teaches us how to live in relation to God; the second, what duties we owe our neighbor.[1]

 [1] Matt. 22:37-40.

 94. Question: What does the LORD require in the first commandment?

 Answer: That for the sake of my very salvation I avoid and flee all idolatry,[1] witchcraft, superstition,[2] and prayer to saints or to other creatures.[3] Further, that I rightly come to know the only true God.[4] trust in Him alone,[5] submit to Him with all humility[6] and patience,[7] expect all good from Him only,[8] and love,[9] fear,[10] and honour Him[11] with all my heart. In short, that I forsake all creatures rather than do the least thing against His will.[12]

 [1] I Cor. 6:9, 10; 10:5-14; I John 5:21. [2] Lev. 19:31; Deut. 18:9-12. [3] Matt. 4:10; Rev. 19:10; 22:8, 9. [4] John 17:3. [5] Jer. 17:5, 7. [6] I Pet. 5:5, 6. [7] Rom. 5:3, 4; I Cor. 10:10; Phil. 2:14; Col. 1:11; Heb. 10:36. [8] Ps. 104:27, 28; Is. 45:7; James 1:17. [9] Deut. 6:5; (Matt. 22:37). [10] Deut. 6:2; Ps. 111:10; Prov. 1:7; 9:10; Matt. 10:28; I Pet. 1:17. [11] Deut. 6:13; (Matt. 4:10); Deut. 10:20. [12] Matt. 5:29, 30; 10:37-39; Acts 5:29.

 95. Question: What is idolatry?

 Answer: Idolatry is having or inventing something in which to put our trust instead of, or in addition to, the only true God who has revealed Himself in His Word.[1]

 [1] I Chron. 16:26; Gal. 4:8, 9; Eph. 5:5; Phil. 3:19.