Sermon on Exodus 20:14 – “Covenant Faithfulness”

Sermon on Exodus 20:14 – “Covenant Faithfulness”

Sermon for Sunday, September 26th, 2021 at First Presbyterian Church at Unionville, NY (BPC)

Old Testament reading:

[Exo 20:22-26 ESV] 22 And the LORD said to Moses, “Thus you shall say to the people of Israel: ‘You have seen for yourselves that I have talked with you from heaven. 23 You shall not make gods of silver to be with me, nor shall you make for yourselves gods of gold. 24 An altar of earth you shall make for me and sacrifice on it your burnt offerings and your peace offerings, your sheep and your oxen. In every place where I cause my name to be remembered I will come to you and bless you. 25 If you make me an altar of stone, you shall not build it of hewn stones, for if you wield your tool on it you profane it. 26 And you shall not go up by steps to my altar, that your nakedness be not exposed on it.’

New Testament reading:

[Eph 5:28-32 ESV] 28 In the same way husbands should love their wives as their own bodies. He who loves his wife loves himself. 29 For no one ever hated his own flesh, but nourishes and cherishes it, just as Christ does the church, 30 because we are members of his body. 31 “Therefore a man shall leave his father and mother and hold fast to his wife, and the two shall become one flesh.” 32 This mystery is profound, and I am saying that it refers to Christ and the church.

Gospel reading:

[Mat 5:27-32 ESV] 27 “You have heard that it was said, ‘You shall not commit adultery.’ 28 But I say to you that everyone who looks at a woman with lustful intent has already committed adultery with her in his heart. 29 If your right eye causes you to sin, tear it out and throw it away. For it is better that you lose one of your members than that your whole body be thrown into hell. 30 And if your right hand causes you to sin, cut it off and throw it away. For it is better that you lose one of your members than that your whole body go into hell. 31 “It was also said, ‘Whoever divorces his wife, let him give her a certificate of divorce.’ 32 But I say to you that everyone who divorces his wife, except on the ground of sexual immorality, makes her commit adultery, and whoever marries a divorced woman commits adultery.

Scripture reading:

[Exo 20:14 ESV] 14 “You shall not commit adultery.


Exodus 20:14 – “You shall not commit adultery.

And a hushed tension fell over the room. This is not everyone’s favorite subject. But as it is one of the commandments it is worthy of our study and understanding.

So far in our study on the commandments we’ve seen that the first four relate to man and God; the vertical commandments. Then there was a commandment regarding relationship of children to their parents. And then one regarding relationships in society – you shall not murder. Now we come to a commandment that regards the relationship of holy matrimony; the relationship of husband and wife in marriage.

“You shall not commit adultery.”

I. The Unfaithfulness of Man

This is a commandment prohibiting sexual relations outside of marriage.

God commanding faithfulness between spouses as they have promised to one another.

And when one abides by this command we say that he has been FAITHFUL.

So then, as the 6th commandment was a commandment of life, the 7th is a commandment of marital faithfulness.

As we have seen with each of the commandments so far in our study, there is more here than first meets the eye. While the commandment expressly condemns adultery, When we look at the whole of Scripture we find that even more is in view.

The clearest example is in Jesus’ own teaching from Matthew’s Gospel:

27 “You have heard that it was said, ‘You shall not commit adultery.’ 28 But I say to you that everyone who looks at a woman with lustful intent has already committed adultery with her in his heart.”

The commandment then does not merely prohibit extra-marital relations, but, as Jesus points out, the intent of the commandment is far more broad. It is against not only adultery, but fornication (that is, pre-marital relations), and other deviant sexual practices all the way down to lust, a sin not of action but of the mind.

Jesus speaks of lust for a very important reason—it is a sin that all have fallen into. A man might avoid all those outward evil actions that break the 7th commandment, yet in his heart he sins when he lusts after a woman with whom he is not married.

Here we see that Jesus comes not to do away with the law, but rather he even expands the law, or at least, our understanding of it. Jesus is not giving a new law, but is telling us … the rest of the story.

In Jesus’ statement we have one of those places that perhaps more than anywhere else in the Scriptures displays the “First use of the law.” That of showing us our sins. Or as St. Paul says “By the law is knowledge of sin.”

Because we have all lusted in our hearts, we have all sinned in breaking the 7th commandment and have thus been unfaithful to our spouses and to our God.

This point is made in the Scriptures and I am making it now because it is intended to draw you to God. You are to recognize your sin and your hopelessness and helplessness in sin, and so rely on the Lord Jesus Christ in faith for the forgiveness of sins and for salvation.

Because, while we have been unfaithful, we have a faithful God. Though we break the covenant, He upholds it. Though we fail again and again, He always comes through, our rock and our redeemer.

II. The Faithfulness God

In the Bible, the marriage relationship is often used as an analogy of the relationship of Christ and His Church. He is the faithful groom and the church is His bride. Sometimes He is called Father and we are his children. Sometimes He is King and we are his servants. But more often God is husband and the church is his wife.

For example:

[Mat 9:15 ESV] 15 And Jesus said to them, “Can the wedding guests mourn as long as the bridegroom is with them? The days will come when the bridegroom is taken away from them, and then they will fast.


[Rev 19:7-8 ESV] 7 Let us rejoice and exult and give him the glory, for the marriage of the Lamb has come, and his Bride has made herself ready; 8 it was granted her to clothe herself with fine linen, bright and pure”– for the fine linen is the righteous deeds of the saints.

Jesus is the bridegroom who is without sin and is always faithful. And so we are called to trust wholly in Him knowing he fulfills his promises. As the church we are to obey him as a wife obeys her husband.

And in Jesus we have one who never abandons his bride. He is faithful to the end.

He said, “And behold, I am with you always, to the end of the age.” – Matthew 28:20b

Similarly Paul told the church in Rome:

“For I am sure that neither death nor life, nor angels nor rulers, nor things present nor things to come, nor powers, nor height nor depth, nor anything else in all creation, will be able to separate us from the love of God in Christ Jesus our Lord.” – Romans 8:38-39

So the Lord is faithful. We must trust in him, and so flee from sexual immorality.

This is what Paul says in 1st Corinthians:

[1Co 6:1-18 ESV] 18 Flee from sexual immorality. Every other sin a person commits is outside the body, but the sexually immoral person sins against his own body. 19 Or do you not know that your body is a temple of the Holy Spirit within you, whom you have from God? You are not your own, 20 for you were bought with a price. So glorify God in your body.

While sin remains in us in this life, we are not to give in to it. Nor are we to identify with it.

This has been a hot-button issue for the last years in some Presbyterian denominations, as some ministers have said “I am gay, but chaste.” They are identifying with their sins. While it is right to admit our sins and say “I have been lustful” it is wrong to say “I am AND ALWAYS WILL BE a lustful person.” Such would be to deny the power of the Holy Spirit to sanctify me.

And this is a goal of the Christians life – sanctification. More specifically here we have the term “the mortification of sin.” This means we are to put sin to death. To have no more of it! With the power of the Holy Spirit to have victory over sin!

You are not to let your sin be your identify, but have you identity in Christ. You are a Christian, a saint … even though you may at times fall into sin, yet God’s promise is valid and He remains faithful even though you have been unfaithful.

Paul admits, “For I do not understand my own actions. For I do not do what I want, but I do the very thing I hate.” (Romans 7:15) And he said that not before he was a Christian, but in the present tense while an Apostle of the Lord Jesus Christ.

Away then with “sinless perfectionism.” This is an aberrant theology that says not only that you SHOULD be sinless, but that you are ABLE to be sinless, and if you sin (they say) you are not a true believer. Nonsense. As Martin Luther said, “we are simultaneous sinners and saints.” Sinning – doing exactly what we don’t want to do; the very things we hate.

So Paul also says regarding sin, and especially the 7th commandment those who are sexual immoral, idolaters, adulterers, homosexuals, thieves, the greedy, drunkards, revilers, and swindlers, he says,

“…And such WERE some of you. But you were washed, you were sanctified, you were justified in the name of the Lord Jesus Christ and by the Spirit of our God.” – 1 Corinthians 6:11

Note that past tense. And such WERE some of you.

This doesn’t mean that they never sinned again! But it does mean that they certainly no longer identified with their sin.

Whatever sin you have committed, don’t let it be who you are and therefore directing your next action. But know that you are a Christian, you are washed in the blood of the lamb, sanctified, and justified in the name of the Lord Jesus Christ and by the Spirit of our God.

You WERE those things. But you ARE now of the church, the bride of Christ whom He sees as perfect in His eyes.

As Christians then, we are to mortify sin.

It is no doubt difficult to change our life patterns. And being commanded not to do something doesn’t always result in changing a person.

So we have the Scriptures an important directive for the mortification of sin. When we get rid of evil we are to replace it with good.

The way the Scriptures talk about it we are to “put off and put on.”

We are to

Put off evil


Put on good

We are to

Put off adultery and fornication and lust

Put on good, “delighting in your wife.” (Proverbs 5:15). We are to put on self-control, one of the fruit of the spirit.

So we are not only called to stop sinning, but to replace it with that which is good. We must develop good habits, go to healthy places (physically and mentally), and seek the Lord at all times, praying “deliver us from evil!”

We are to put on the good.

A man, Genesis tell us, is to “cleave” to his wife. To attach, Physically as one flesh. And spiritually, mentally, emotionally, as devoted to her. Not allowing opportunity for the evil of lust or anything more heinous to arrive.

This pattern of “putting on” and “putting off” applies to all of our sins. We could also say:

Put off drunkenness or drug


Put on Bible reading, socializing, fellowship, volunteering. Filling your time with something so that you do not get drunk or have any temptation to do so.

Our Confession says the following regarding sanctification and the mortification of sin. It speaks of all of us as Christians, saying

They, who are once effectually called, and regenerated, having a new heart, and a new spirit created  in them, are further sanctified, really and personally, through the virtue of Christ’s death and resurrection, by his Word and Spirit dwelling in them: the dominion of the whole body of sin is destroyed, and the several lusts thereof are more and more weakened and mortified; and they more and more quickened and strengthened in all saving graces, to the practice of true holiness, without which no man shall see the Lord.

This is something God does within you through the Holy Spirit. The same God who justified you on the cross will sanctified you through the work of the Holy Spirit.

Since God is faithful, He will do it.

So salvation is not earned by OUR holiness, nor is salvation maintained by OUR holiness, but both our justification and our sanctification are works of God. So that He gets all the glory.

And one day, our sins, even our sexual sins, will be no more.

Know that there is forgiveness, there is grace in the Lord Jesus Christ, even for sexual sins.

Consider the woman at the well. She had five divorces and was not married to the man with whom she was now living, Yet she came to believe in Jesus Christ and having salvation in him.

And there is King David, the adulterer, who slept with another man’s wife (Bathsheba) but yet was forgiven by the grace of God.

So do not let your sins, especially your sexual sins, define you. But go to the Lord in faith praying for forgiveness because He is faithful and just to forgive us our sins and cleanse from all unrighteousness.

Then, going forward, taking off that which is evil, and putting on that which is good, let our love be patterned after Jesus Christ’s that it be sacrificial, committed, forgiving, and of a servant heart, and faithful in all things.

If you have been deceived by another, know that God is faithful. There is no shadowing of turning within Him. His promises are all yes and amen. Let us have faith in He who is faithful, and we pray that we live according to his commands; he who has forgiven us though we sin against Him. There is no better way to understand God’s character than in the title of the hymn “Great is Thy Faithfulness.” Though we have been unfaithful, God is and always will be faithful to his covenant.