I have regularly argued that the way to holiness is not through teaching that the Mosaic law is binding on the Christian conscience and that it must be obeyed. A mentality of ‘law-keeping’ is not the way to grow in grace. This does not mean that we cannot learn from the OT law. We can. Christians living in the Spirit mine the Scriptures, for they know that among other things they are profitable ‘for training in righteousness’ ‘(2 Tim 3:16). Yet they frame all they discover about righteous living within gospel realities.
Let me illustrate what I mean. How should a preacher persuade believers to turn away from adultery? Below is an example of how such an exhortation may be made. Note it uses the OT but does so recognising its redemptive-historical setting. And note too that the gospel provides the main framework and rationale for rejecting adultery.
‘My brothers and sisters, we ought to loathe adultery. David’s adultery, although forgiven, brought ramifications that devastated his family. God is opposed to adultery and adulterers. Don’t you know that in the OT the very heart of the law of Moses condemned adultery in its Ten Words. So great was God’s hatred of adultery among his OT people that the law demanded the sentence of death for adulterers. Does this not tell us how seriously God views it? Indeed the law was only codifying and formally forbidding what men universally know in their hearts. All cultures oppose adultery. All codes of behaviour condemn it.
But brothers and sisters, unconverted folks may need to be reminded adultery is a sin and will bring judgement for they harden their hearts against God, but we should not. We have the life of God in our souls. This life finds adultery unthinkable. Every instinct of your renewed nature is repelled by adultery. God’s Spirit within lusts for purity not impurity.
It is to this end of purity that we have been justified in Christ. Why did we seek justification? We did so because we wanted to be cleared of sin. We wanted to be done with it. We saw how sinful and offensive it was and how deserving of judgement. We wished to be finished with it. That is what we were saying when we came to God in repentance seeking his forgiveness. How then can we allow ourselves to be attracted again to that same sin that we died to in the death of Jesus that we may be freed from it? We wished to cease being slaves of sin and become instead slaves of righteousness (Rom 6). That is what we have been freed from accusation and sin to become. Our calling is to yield our bodies as instruments of righteousness and not impurity.
How can you abuse your body in this way? Your body is not yours to do with what you will. It is bought with a price and belongs to the Lord. Glorify God with your body do not use it to bring disgrace on his name. Christ’s death was precisely because of the horror and ugliness of adultery. He died that we may be cleansed from sins like this and lives that he may enable us flee them. The grace of God renews us and recreates us in the image of Christ. Don’t you want to be like Christ? Of course you do, this is the desire of every renewed heart. It is the longing of every son of the Kingdom. The Kingdom of God and Christ is a kingdom of righteousness, loyalty, truth and faithfulness. Adultery is the very opposite of this. Don’t you know that no adulterer will inherit the Kingdom of God. The Eternal City of God in which the righteous dwell has no adulterers. Nothing impure enters there. We read in Revelation that ‘outside are adulterers’
Brothers and sisters, we are people who have been delivered from sin, we have a nature that is altogether new, we are a new creation in Christ living for a new heavens and new earth in which righteousness dwells let’s put off these impurities of the old life because of which the wrath of God is coming and let us live as the people of God with pure hearts that hate every suggestion of sin and unrighteousness…’
Much more of course could be said but I think this sample-sermonette illustrates how the gospel creates a godly people and how turning away from adultery can be considered an imperative of the gospel.