Skip to main content

A Biblical Catechism on Sex and Marriage: Introduction

[This post begins a series of posts entitled 'A Biblical Catechism on Sex and Marriage'.  The intention is to provide basic material for further instruction by a trusted teacher of God's Word in a church that is committed to Biblical authority.  Both Jesus and Paul saw teaching on sex and marriage as part of their missionary proclamation: a catechism or teaching on this subject, and ethics overall, is an essential part of Christian missions.  After all, missionary proclamation is an invitation to live under God's righteous rule, the Kingdom of God.]

Note: All quotations from Scripture in this series, unless otherwise noted, are from the New Revised Standard Version.

Formation as God’s people is first and foremost a matter of being instructed in and of obedience to His commandments.  Through Scripture, God teaches His people to walk in His ways.

In the Old Testament, God instructs Israel in the ways of righteousness.  He says,

Deuteronomy 6:4-9  "Hear, O Israel: The LORD our God, the LORD is one.  5 You shall love the LORD your God with all your heart and with all your soul and with all your might.  6 And these words that I command you today shall be on your heart.  7 You shall teach them diligently to your children, and shall talk of them when you sit in your house, and when you walk by the way, and when you lie down, and when you rise.  8 You shall bind them as a sign on your hand, and they shall be as frontlets between your eyes.  9 You shall write them on the doorposts of your house and on your gates.

As we will see in this guide, the instruction God gives to His people includes clear teaching on sex and marriage.

Jesus, too, taught his disciples how to live according to the righteousness of the Kingdom of God (Matthew 5-7).  To enter God’s Kingdom is to begin to live under His reign and according to His commands.  Jesus’ Sermon on the Mount begins with invitation, continues with moral teaching, and ends with a warning.  His invitation is a promise of blessing for all who will leave their exile in sin and return to God’s reign: ‘Blessed are those who hunger and thirst for righteousness, for they shall be satisfied’ (Matthew 5:6).  One of the topics in Jesus’ teaching on the righteousness of the Kingdom of God is that of this study: sex and marriage (cf. Matthew 5:27-32).  Jesus concludes the Sermon on the Mount with a warning to those choosing not to live according to God’s commandments, whether average persons or those in active ministry:

Matthew 7:21-23 "Not everyone who says to me, 'Lord, Lord,' will enter the kingdom of heaven, but only the one who does the will of my Father in heaven.  22 On that day many will say to me, 'Lord, Lord, did we not prophesy in your name, and cast out demons in your name, and do many deeds of power in your name?'  23 Then I will declare to them, 'I never knew you; go away from me, you evildoers.'

Paul’s ministry also involved a welcome through the Gospel, a teaching about how to live righteously, and a warning about God’s coming judgement.  The apostle proclaimed the good news of salvation from sin through the death of Jesus Christ.  This was a message of welcome to everyone, even the worst of sinners (and Paul included himself in that).  He then taught new converts about how to live righteous lives.  He established the church in Thessalonica in just a few weeks, but in 1 Thessalonians he writes to remind these new believers what he had already taught them in that short time (1 Thessalonians 4:1-2).  His ethical teaching included personal, sexual ethics (4:3-8), community ethics (4:9-10), and their relation to those outside the church (4:11-12).  He concludes with a warning not to be caught unprepared when the Day of the Lord—God’s judgement—comes swiftly.  Rather, Christians are to live for Christ:

1 Thessalonians 5:8-10 But since we belong to the day, let us be sober, and put on the breastplate of faith and love, and for a helmet the hope of salvation.  9 For God has destined us not for wrath but for obtaining salvation through our Lord Jesus Christ,  10 who died for us, so that whether we are awake or asleep we may live with him.

Being a Christian involves being part of a community, regular worship, sharing the history and culture of a particular people, and affirming its convictions, practices, liturgies, and mission.  It is about all such things, but it is firstly a matter of walking in the ways of the Lord.  Certainly we affirm that salvation is by grace through faith and not of our own works (Ephesians 2:8-9), but we also affirm that this salvation is a matter of our being ‘created in Christ Jesus for good works’ (Ephesians 2:10).  By God’s grace—His forgiving and transforming grace in Christ Jesus and the Holy Spirit—we are a people committed to walk in the ways of the Lord (Romans 8:3-4).  By the same token, if we do not walk in His ways and continue in sin, including sexual immorality, we will not enter the Kingdom of God (cf. 1 Corinthians 6:9-11; Galatians 5:19-21; Ephesians 5:5; 1 Thessalonians 2:12).  We embrace the ‘Welcome’ of the Good News to all; we follow the teaching on righteousness in God’s commandments; and we live soberly, aware of God’s coming judgement.

The eleven lessons in this booklet are meant to guide communities in God’s teaching for their lives in one area of God’s commandments for holy living: sex and marriage.  Hear, then, the teaching of God in His holy Word.