What’s the context? Is Jesus, after causing the mob to lay down their stones by pointing out their own sinful hypocrisy, and showing mercy to the woman, now telling her, “Now, don’t sin or else”? If the “go and sin no more” is about becoming literally impeccable, then this is not a word of mercy to her, but a word of condemnation–if she cannot become impeccable then what?
But in the context she has been set free from the cruelty of the hypocritical mob, Jesus declares mercy to her, and then sends her on her way–to “go and sin no more”. In the narrowest sense it is a call for her to recognize the mercy she has just received and to no longer live in the sin (adultery) she had been living in. That is not a harsh command, but a loving call and invitation.
The context matters here.
In the larger scope of biblical teaching we can know that impeccability is never supported, because Scripture presumes that God’s people need to repent, to confess their sin, to abide in Christ. St. John writes, “If we say we have no sin, then the truth is not in us”, that’s a statement for us, for Christians; as is the following statement, “But if we confess our sins, He is faithful and just to forgive us our sins and cleanse us from all unrighteousness” (1 John 1:8-9).
Christians do not deny that we are sinners, but instead confess that we are sinners–we make bold our confession, trusting in God’s grace, in the forgiveness that God freely and graciously gives us in Christ.
“Go and sin no more” is not, and cannot, mean “If you try hard enough, you can attain your own righteousness”; it cannot mean “watch out, if you screw up again, God is going to get you”. Christ preaches mercy to the woman, He gives her freedom–the freedom to experience a new life, no longer enslaved to the life of adultery she was living in, but a call to live in the new-found freedom and mercy she has received.
And that becomes a blessing to us all, who in our sin come face-to-face with the harshness of the Law, which justly condemns us. We do not need a mob of hypocritical sinners to threaten us; the Law itself is just and holy and condemns us all in our sin. The Law cannot make us righteous; only grace can free us to a life no longer defined by our sin.
“Do not be deceived: neither the sexually immoral, nor idolaters, nor adulterers, nor men-bedders, nor thieves, nor the greedy, nor drunkards, nor revilers, nor swindlers will inherit the kingdom of God. 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 6:9-11
Does this mean none of the Corinthians ever sinned? Of course they did, otherwise Paul’s epistle to them almost makes no sense,
“But you yourselves wrong and defraud—even your own brothers!” (1 Corinthians 6:8), that’s the verse immediately preceding the above.
The Apostle is speaking of the past lives of the Corinthians, but they have a new life in Christ–and it is precisely that new life in Christ that they should aspire for, and thus the wrong they do–their sin–is even more unacceptable. Why are they sinning when they have been freed from sin?
That’s what Paul gets on about in Romans 6 as well, after having said, “Should we go on sinning so that grace may abound? Heavens no!” he follows it up by reminding the Romans of their baptism, they have died with Christ, buried with Christ, they have a new life in Christ–for the one who has died has died to sin, so why go on sinning? Instead we are to think of ourselves as dead to sin and alive to God.
It is never impeccability that is being preached, but rather genuine condemnation of sin, the use of the Law to both reveal our sin and to call us to repentance and change our way of life; and the preaching of the Gospel to declare that we are forgiven, there is mercy, grace sets us free.
So “Go and sin no more” is not an expectation of impeccability; it is a call and invitation to new life, “Where are your accusers?” “Sir, they are gone” “Neither do I condemn you, go and sin no more” That’s a benediction, a sending forth with blessing, in mercy, and invitation to live differently than before.