What happens when a Christian sins?

But if, in our endeavour to be justified in Christ, we too were found to be sinners, is Christ then a servant of sin? Certainly not! For if I rebuild what I tore down, I prove myself to be a transgressor.

Galatians 2:17-18

What happens when a Christian sins? That’s the question Paul raises in verse 17 - “If... we too were found to be sinners?” He isn’t talking about the non-believer who doesn’t know Jesus. He isn’t talking about the backslider who has turned his back on Christ. No, these are genuine Christians who are “endeavour(ing) to be justified in Christ,” - who are living day-by-day trusting in Jesus, following Jesus and loving Jesus - who are the same people who then fall into sin.

Literally, the phrase means “found out” (heurethemen - discovered). Meaning, not simply, that your friends point it out to you (“Aha! I saw what you did!”), but more so, that you are aware of a particular sin in your own life - an ongoing struggle with temptation, perhaps; or a serious wrong that you have committed against your own conscience and against God.

What do you do then with your sin as a Christian? How are you likely to react to your sin as a believer?

What Paul says next is personal, practical and real. He says to us: You are going to be tempted to do one of two things. You are either going to excuse it or justify it.

Excusing our sin

The first common reaction to sin is to try and excuse it. Paul says to the Christian, “Is Christ then a servant of sin? Certainly not!” What he is saying is: Just because you know that Jesus died on the cross for your sin does not mean you have a free pass to keep on sinning. You need to stop. You need to repent - that is, to turn away from your sin and to face up to God. In fact, it even means that if the sin that you’ve committed is a crime punishable by law, you need to submit yourself to that punishment.

Now, when Paul asks the question, “Is Christ then a servant of sin?” it’s not as strange a question as you might think. When someone gets the gospel for the first time, it always sounds too good to be true. God sent Jesus to take the punishment for our sins in our place - while we were still sinners. He died to pay for all our sins - past, present and future. Many people are going to hear that and think it is a con. They are going to think, “What’s the catch?” Why? Because it sounds too good to be true. It sounds like God is handing out a blank cheque. It that really happened, what would stop us from taking advantage of God’s generosity and abusing it?

And it needs to be said, that is a real temptation for us as Christians - to take God’s grace for granted and to use it as an excuse to keep on sinning. Paul says, “Certainly not!” That’s the attitude we need to take towards our sin, “No way am I doing that!” “No way am I going to use Jesus as an excuse to keep on cheating on my wife.” “No way am I going to use my church attendance as a cover up for my greed.” Paul is serious about sin, but it is because Paul is even more serious about Jesus. No way is Jesus to be used as an excuse, a free-pass, a licence to sin against other people, against our conscience, against God. No way.

So, that’s the first temptation for the Christian who has fallen into sin: to excuse it, to minimise it or to take it for granted. But the second temptation is the one he really wants us to sit up and take notice of. It is the temptation to justify that sin.

Justifying our sin

For if I rebuild what I tore down, I prove myself to be a transgressor.

Galatian 2:18

Paul gets personal. If I rebuild; what I tore down; I prove myself (literally, establish myself) as a sinner. Paul is speaking from his experience of struggle with his own sin and openly confesses, “Here is what I am most tempted to do with my sin: To justify it.”

If you have a bible, it’s worth looking back to the context of his argument in Galatians Chapter 2, especially beginning with verses 11 onwards where he mentions the apostle Peter’s visit to Antioch. You see, there, Paul confronts Peter’s sin in public. What was it that Peter did that was so horrible and so serious that Paul had to bring it up on Sunday morning in church in front of all his friends and family? Did Peter embezzle the church funds? Did Peter run away with his secretary? Well no, it was none of that, actually. All Peter did was he stopped hanging out with the non-Jewish friends after church. He was afraid, Paul tells us, of the “circumcision group”, that is, Peter was afraid that word would get around that he was breaking the traditional Jewish laws by mixing with Gentiles (non-Jews) and this would result in problems for the Christians back in Jerusalem. He was afraid that members of the “circumcision group” would use his behaviour as an excuse to carry out hate-crimes against the church in Jerusalem.

So, if you think about it, Peter was acting out of love, out of concern and out of consideration for his brothers and sisters in his home church. Paul saw things quite differently: Peter was acting out of fear. In itself, that wasn’t the problem. The problem was that out of fear, Peter decided he would turn to the law instead of gospel, to deal with his fear.

Again, we might read this and say, “What’s the big deal?” Peter didn’t break any laws. Peter didn’t hurt anyone. What was the big deal?

The reason we say that is because we think that sin means law-breaking. That’s the most common understanding of what sin is: It’s breaking a set of rules. We think that sin means breaking the law. But notice how Paul defines sin quite differently here. Look at what he says in verse 18: “For if I rebuild what I tore down, I prove myself to be a transgressor.” What is he saying? With respect to the law, it’s not the person who breaks the law who is the sinner, it’s actually the person who tries to keep the law. That’s a surprising definition to find, of all places, in the bible, isn’t it? Here is a verse that defines the sinner - the transgressor, as Paul puts it - not as the lawbreaker but the lawmaker.

“If I rebuild what I tore down,” Paul says. Remember that Paul used to be a Pharisee. He was the Hebrew of Hebrews, who kept the law, perfectly. This was a guy who memorised Genesis to Deuteronomy, word for word. This a guy who knew the rules, who lived by the rules, who enforced the rules. But when Paul became a Christian, he considered everything a loss compared to the surpassing greatness of knowing Christ Jesus as Lord, for whose sake he lost all things (Philippians 3:8). What does that mean - to consider everything a loss? (He even calls it “rubbish” - a euphemism, as the word he actually uses much, much more offensive than trash)

What is he referring to? Paul is talking about his confidence in his own track record. That’s what the law represents. For Paul the Pharisee, the law was a way to fix things. But for Paul the Christian, he had come to realise that the law was never meant to fix anything. It was only there to uncover our brokenness and sin. The only solution that God has given us for our sin is Jesus. His death on the cross pays the full penalty of sin and credits our account with the full benefits of his righteousness.

Looking to our Saviour

As Christians we know that. But Paul is saying to us, we tend to forget; and the times when we are most tempted to forget is when we sin. We look to the law for a way to make up for our sin. We look to the law for a solution that will allow us to pay for our sin. We look to the law for a means to feel better about our sin. But all the law does is condemn us of our sin. What does Paul say again? “If I rebuild what I tore down, I prove myself to be a transgressor.”

To turn back to the law, after having known Jesus and trusted in his salvation by grace through faith alone, is to establish ourselves firmly in our guilt as sinners. It is, in effect, to say to Jesus, “Thanks for dying on the cross for me, but I’ll take it from here.” Paul says, “If righteousness could be gained through the law, Christ died for nothing!” (Galatians 2:21)

And yet, don’t miss the fact that Paul is speaking about his own sin and his own struggles with sin. Verse 19: “For through the law, I died to the law so that I might live for God.” Verse 20: “The life I live in the body, I live by faith in the Son of God who loved me and gave himself for me.” Verse 21: “I do not set aside the grace of God...”

Why does Paul get so personal here? Just a few verses earlier, Paul had been talking about Peter’s sin of hypocrisy, of fear of man, of compromising the gospel - and Paul mentions how he confronts Peter of his sin. But you see, Paul is confronting sin in a brother’s life not with the law, but with the gospel. And Paul then turns and says to us, “Quite frankly, the only difference between Peter and myself is the grace of God.”

I met a pastor a few years back who was in a counselling situation with someone who had committed a horrible sin. “How could he do that?” he said to me. “How could a Christian sin like that against someone he loves?” Over the years, as friends have shared with me their struggles with sin, I admit that at times, I have been tempted to say the exact same thing, “How could this happen? How could you let this happen?”

This passage from Galatians soberly reminds me that as I encounter sin in another believer’s life, I should be all the more aware of my own sinfulness and I should be all the more aware of the overwhelming grace of God available through Jesus Christ. Like Paul, I should be able to say, “There, but the grace of God, go I.”

If you are a non-Christian, you need to know that the only thing differentiating you and me is not our sin. We are both sinners. That is not to say, however, that there is no difference between the Christian and the non-Christian. We are both sinners, yes, but God has forgiven the sin of the Christian. He has done this not based on the law, not based on the track-record of the believer, not based on the goodness of the Christian, but purely out of his grace towards sinners. Sinners, like you and me.

But if you are a Christian, and you know this gospel - this message of free grace and forgiveness - what this passage is saying to us is: Don’t be surprised by sin. Don’t be surprised by sin - whether it is sin in others or sin in your own life - to the point that when sin happens, you are tempted to excuse your sin or justify your sinfulness. Instead confess your sin to God. Turn to Jesus alone who died for your sin and rose for your justification. There is forgiveness and restoration at the cross.

Most important of all, don’t wait till you are caught in a serious situation of sin before you start looking to Jesus as your Saviour. For Paul, apostle though he was, the reason he was aware for his struggles and sinfulness, wasn’t because he was constantly absorbed with himself. It wasn’t because he was vigilantly looking out for this or that trace of sin. Quite the opposite actually, Paul was constantly focussed on one thing: Jesus. All his life, Paul never got over the fact that Jesus Christ died on the cross for him, a sinner. Every day, Paul looked to his Saviour. Every day Paul was conscious of Jesus’s sacrifice, “The Son of God who loved me and gave himself for me!” And Paul knew, that in Christ, he was fully accepted; that in Christ, he was absolutely loved.

Alas, and did my Saviour bleed

And did my Sovereign die?

Would He devote that sacred head

For such a worm as I?

Was it for sins that I had done

He groaned upon the tree?

Amazing pity, grace unknown

And love beyond degree

My God, why would You shed Your blood

So pure and undefiled

To make a sinful one like me

Your chosen, precious child?

(“Alas, and did my Saviour bleed,” original words by Isaac Watts, additional words by Bob Kauflin, Sovereign Grace Music)