In the last post, we looked at how it's possible to get justification right but sanctification wrong, and the way that has terrible consequences, leading believers either into despair or pride.
Which leads to the question, how do we understand sanctification by grace through faith, rather than have an implicit 'Nike view' of growing as a Christian?
The key is how we understand the sin which we are to put off, and the Christlikeness we are to put on.
In the Old Testament, a key category for understanding sin was idolatry. Both in the nations, and in Israel herself, idolatry was regularly the object of fierce prophetic denunciation.
In the New Testament, this recognition of idolatry as sin in its fundamental form is resolved into a new key.
In Paul’s letter to the Romans, chapter 1, the Apostle declares his great confidence in the gospel, because it is the power of God for the salvation of all who believe, the Jew first and also the Greek. And it is that power because in the gospel, the righteousness of God is revealed, through the faithfulness of Jesus Christ, for everyone who has faith. And then Paul starts to unfold that righteousness - in particular, it starts with the fact that God does not wink at sin, or sweep it under the carpet, but is impartial in his wrath against all sin by all those who by their wickedness suppress the truth … or in other words, do not honour God or give him thanks, but exchange the glory of the immortal God for images resembling a mortal human being or birds or four footed animals or reptiles.
So far, this sounds like a standard denunciation of idolatry. But then things take a deep turn. The Apostle goes on to say that God’s response to this was to give them up “in the lusts of their hearts” to impurity, because they exchanged the truth about God for a lie. That phrase, “in the lusts of their hearts” is a crucial moment, technically what is called epexegetical, or explaining in new words the idea previously mentioned.
And is right there that Paul identifies the spiritual essence of idolatry - the Greek word he uses for ‘lust’ is epi-thumia, literally over-desire. Sin is idolatry at its essence, and idolatry is always a movement of the heart’s desire towards some element of creation, seeing in it a source of life and joy and hope, and over-desiring it. That can be an over- desire for a bad thing, such as an immoral sexual relationship (Rom 1.26-27); equally, it can be an over- desire for a good thing, but longing for that good thing as though it were an ultimate thing.
And as the Apostle catalogues, it is from this epi-thumia, this over desire of the heart, that all other sins flow. What's interesting is that the New Testament letters are almost incapable of talking about sin without locating its driving force in epi-thumia. It is mentioned constantly as the essence of sin, although sadly is often translated in different ways, meaning that we can miss its significance. Of course, in this, the Apostles are only following the lead of Jesus, who was crystal clear that it was from within, from the human heart, that evil originates.
The point is this: unless we address the heart as we strive for sanctification in ourselves, and call for it in others, we will never really have any depth in our repentance.
And the only thing that can melt the heart is grace, the grace of God in the cross of Christ.
The reason is that it is only that grace which can sufficiently capture the heart’s desire by its glory and beauty, so that the heart’s epi-thumia, its over-desire, can be weaned off from whatever it is set on, and instead set properly on Jesus Christ. As believers sees Christ’s sacrifice and perfection, specifically in relation to their heart’s desire which is idolatrously set elsewhere, so they set their hearts rightly upon him, and the driving force of that sin is broken in their lives. Here is how to preach sanctification by grace through faith, as the perfect complement to justification by grace through faith.
The terrible alternative is that we preach moralism. If we don’t address the heart, but simply inform the mind, or inflame the emotions, or discipline the body, or constrain the will, the only change we can expect to see is external change, a compliance perhaps, but not the newness of life to which we are called. Of course, all those things are good aspects of ministry, but if we don’t speak to the heart, it will be like plucking off greenery, instead of pulling up the weed by the roots. And the tragic consequence is that this moralistic failure - or perhaps even worse, moralistic success! - will erode the joy and great freedom of justification by grace through faith.
That’s why it’s so crucial to have a ministry that teaches sanctification by grace through faith, right alongside justification by grace through faith.