The seventh commandment: purity

This week's questions

Which is the seventh commandment? The seventh commandment is, Thou shalt not commit adultery.

Question 70

What is required in the seventh commandment? The seventh commandment requireth the preservation of our own and our neighbour's chastity, in heart, speech, and behavior.

Question 71

What is forbidden in the seventh commandment? The seventh commandment forbiddeth all unchaste thoughts, words, and actions.

Question 72

Last week the sixth commandment guarded our neighbour's life; the seventh guards marriage, the deepest bond of body and love, and the purity of us all. Question 71 gives what is required, Question 72 what is forbidden.

God's gifts: marriage and single life

The commandment protects something good. God made man and woman and joined them as "one flesh" (Genesis 2:24), and Scripture says, "Marriage should be honored by all" (Hebrews 13:4). The Westminster Confession teaches that marriage "is to be between one man and one woman" WCF 24.1. Proverbs bids a husband "rejoice in the wife of your youth" (Proverbs 5:18): the love of husband and wife is a joy to thank God for. Question 71's first proof text asks husband and wife to give each other what they owe:

But because there is so much sexual immorality, each man should have his own wife, and each woman her own husband. The husband should fulfill his marital duty to his wife, and likewise the wife to her husband.

1 Corinthians 7:2-3

In the same chapter Paul calls single life a gift from God as well (1 Corinthians 7:7-8), and says that the unmarried can give themselves to the Lord's work, holy in body and spirit (1 Corinthians 7:34). The Heidelberg Catechism sets the two side by side: we are to "live chastely and modestly, whether in holy wedlock or single life" Heidelberg Catechism, Q. 108.

Pure in heart, speech and behaviour

Question 71 places chastity in the heart, the tongue and the life. In Question 72's first proof text Jesus says that adultery comes "out of the heart" (Matthew 15:19), and in the next he goes deeper:

But I tell you that anyone who looks at a woman to lust after her has already committed adultery with her in his heart.

Matthew 5:28

Job made "a covenant with my eyes" (Job 31:1), and the Larger Catechism counts "watchfulness over the eyes and all the senses" among this commandment's duties Larger Catechism, Q. 138 and forbids, among much else, "lascivious songs, books, pictures" Q. 139: what we watch and read on our screens belongs here. So does speech. Paul puts thanksgiving in place of "crude joking" (Ephesians 5:4), and asks that our speech "always be gracious, seasoned with salt" (Colossians 4:6). So does our conduct (1 Peter 3:2), for the body is "a temple of the Holy Spirit", bought at a price (1 Corinthians 6:19-20; Heidelberg Catechism, Q. 109). Nor is purity ours alone: Paul warns that no one should "violate or exploit his brother in this regard" (1 Thessalonians 4:6), and the Larger Catechism asks us to preserve chastity in ourselves and others.

Some read this commandment and remember a past they are ashamed of. To a church where some had lived in sexual sin Paul writes, "But you were washed, you were sanctified, you were justified" (1 Corinthians 6:11). David, after his fall, prayed, "Create in me a clean heart, O God" (Psalm 51:10). As the English pastor Matthew Henry says, "There is tender mercy under all the Divine requirements, and the grace and consolations of the Spirit will enable us to attend to them" Matthew Henry. If you have struggled long, do not fight alone; walk with someone you can trust. Those who have suffered sexual abuse are not guilty. The sin belongs to the one who did it; seek help from someone you trust, from your pastor and from trained services.

On divorce and remarriage the churches differ. The Westminster Confession holds that nothing but adultery, or wilful desertion that neither church nor magistrate can remedy, can dissolve the bond of marriage WCF 24.6, and allows the innocent party in adultery to divorce and remarry 24.5. The Catholic Church teaches that a sacramental marriage cannot be dissolved, though it may declare that a marriage was never validly made (an annulment). The Orthodox Church may, in some cases, allow a second marriage in a spirit of repentance. If your marriage is shaking, do not decide alone: seek your pastor and people you trust. If you are in danger at home, your safety comes first. What does the Bible say about sex and marriage? treats the subject more fully.

To ponder this week

What do I let into my eyes and thoughts this week, and how can I guard my neighbour's purity as well as my own? At the end of each day, look back quietly on what you saw and said, and pray Psalm 51:10. If you are married, thank your husband or wife for one thing in words; if you live alone, spend time with your church family.

Practice