The Christian life has this baffling paradox at its heart: we are simultaneously sinners and saints. We are both able to sin and able not to sin.

As saints, we’ve experienced the power of new birth (2 Corinthians 5:17) and tasted “the firstfruits of the Spirit” (Romans 8:23). Yet despite these miraculous realities, we keep on sinning, to our great dismay and shame. And if we think we don’t sin, John tells us we’re deceiving ourselves (1 John 1:8). As much as we wish it were not so, saints still sin.

Sinning as a saint can cause two opposite (and equally) wrong reactions. On the one hand, we can respond with prideful presumption in our power to overcome sin. On the other hand, we can react with helpless despair in the face of our persistent sin. What should we do? One early church pastor, Augustine of Hippo (354–430), has given us categories for understanding our relationship to sin, as well as hope for saints in the fight with sin.

Sin and (In)Ability

The arc of salvation history — creation, fall, redemption, consummation — frames Augustine’s categories for man’s relationship to sin (see, for example, On Correction & Grace XXXIII; The Enchiridion CXVIII). In the garden before the fall, Adam was able to sin (Latin posse peccare). And sadly, he did (Genesis 3:6).

After the fall, Adam’s original sin corrupted all mankind such that all men were not able to not sin (non posse non peccare). Fallen man’s inability to live righteously is so complete that Scripture calls us dead in sin (Ephesians 2:1–2). Only by Christ’s death and resurrection are we made alive and by the Spirit newly able not to sin (posse non pecarre). The power of sin over us has been broken (Romans 6:6–7).

“Pride is a deceiver. Despair is a liar. And only grace brings hope.”

Yet the presence of sin has not disappeared (Romans 6:12). This is the present experience of saints who still sin. We are still able to sin and now able not to sin. Because of the frustrating reality of ongoing sin, we groan with anticipation (Romans 8:23) for the day when we will be gloriously not able to sin (non posse pecarre). We hope in the day when we will see Christ face to face (1 Corinthians 13:12) and when all things will be made new (Revelation 21:1–8).

But in the meantime, we can believe more deeply the indispensable truth that Augustine helpfully reminds us of: in Christ, we really are able not to sin. As a pastor, Augustine gave these categories both to situate the Christian’s present fight against sin and to offer hope for future complete freedom from sin.

Neither Pride nor Despair

Our experience is one of sinning saints whose fallen nature is still being renewed. In this state of simultaneous ability to sin and not to sin, we are constantly in danger of two wrong responses, depending on our individual circumstances and personal proclivities.

First, we can slip into a pattern of presuming we can overcome our sin alone. Pride deceives us into indifference and apathy concerning the means of God’s grace. We assume that everything is under control, overlooking the subtleties of sin’s temptation and overestimating our ability to fight in our own strength.

Second, we sometimes fall into a deep despair where we feel helpless in fighting sin. Our old patterns of sin seem insurmountable. Our despair lies, saying there is nothing we can do, so we might as well indulge that desire again.

Pride is a deceiver. Despair is a liar. And only grace brings hope. So when it comes to a Christian’s ability not to sin, Augustine navigates between both prideful presumption and helpless despair by emphasizing several truths from Scripture about our ability not to sin.

Your Ability Is a Gift

A performance mentality can lead us to take a “just do it” approach to fighting sin. If I just try harder, just work smarter, just remember better, then I’ll overcome my addiction to pornography, my ever-present anxiety, or my gluttonous eating and drinking habits. Such an approach puts all the confidence in our will. Augustine warns though that man’s “free choice is sufficient for evil, but hardly for good” (sermon 156.12). If we depend on our unassisted will to be good, we will end up addicted to our evil desires.

But maybe you are not like that. Maybe you recognize that fighting sin is hard and that you need a little help. To you, grace sounds like a great performance additive to get you over the hump. This mistake is subtler but just as deadly.

This thinking, Augustine explains, claims that “the grace of God is help for doing things more easily.” It suggests man’s ability is like his power to row a boat, and God’s grace is like the wind in the sails. That sounds like great cooperation, but in reality, it makes God’s grace unnecessary. We could always row on our own without the wind (sermon 156.13). God’s grace is not optional like that; it’s absolutely necessary. Jesus did not say, “Without me you can indeed do something, but it will be easier through me.” He said, “Apart from me you can do nothing” (John 15:5). Without the power of the Holy Spirit, we are powerless to conquer sin in a way that honors God.

“Grace gives control of us back to ourselves.”

Our ability to fight sin and do good works is a gift, for, as Augustine loved to quote, “What do you have that you did not receive?” (1 Corinthians 4:7). Every temptation resisted, every thought captured, every sin killed is accomplished by the grace of the Holy Spirit’s power at work in us.

Your Ability Is Real

Should we then sit back and wait for grace to quell the anger in us or calm our inordinate fears? Are we led like a droid into battle, completely acted on but never really acting ourselves? No, says Augustine, “you both act and are acted on” (sermon 156.11).

Grace does not work like radio waves remotely controlling a droid. Grace renews our minds and restores our fallen natures. Grace gives control of us back to ourselves. God does the miraculous work of making us alive and the equally miraculous work of restoring our fallen nature. Therefore, when we resist sin, it is really us resisting it. The ability that God restores in us is a real ability. Augustine explains,

When you hear, As many as are led by the Spirit of God these are God’s sons, don’t slacken off and give up. After all, God is not building his temple out of you as out of stones which can’t move themselves. . . . That’s not what living stones are like (1 Peter 2:5). You are being led, but you too must run; you’re being led, but you must follow; because when you do follow, it will still be true, that without him you can do nothing. Because it does not depend on the one who wills or the one who runs but on God who has mercy (Romans 9:16). (sermon 156.13)

All the commands in Scripture have no meaning if our ability is fake. To take just one example: Paul says, “Put to death therefore what is earthly in you: sexual immorality, impurity, passion, evil desire, and covetousness, which is idolatry” (Colossians 3:5). Paul’s assumption is that we really do act. Our ability not to sin is real. Yet that restoration process is not immediate; we are being transformed.

Your Ability Is Incomplete

Although we are able not to sin, sin still plagues us. Scripture gives no promise of sinlessness in this life; indeed, it says the opposite (1 John 1:8). We’re never promised total victory over sin.

“Every sin killed is accomplished by the grace of the Holy Spirit’s power at work in us.”

Instead, the renewal we experience in our life is a foretaste of future glorification. We will win battles against sin in this life, but we should not expect to win the war. We have the ability not to sin, but not the ability to eradicate sin. Our ability in the fight against sin, then, is incomplete until Christ comes again.

We cannot yet rest in victory. Augustine reminds us that “the life of the just in this body is still a warfare, not a triumphal celebration. One day, though, this warfare will have its triumphal celebration. . . . Here is the language of triumph. . . . Death has been swallowed up in victory. Let those celebrating their triumph say, Where, death, is your sting?” (1 Corinthians 15:54–55; sermon 151.2).

The war against sin can be exhausting. And Scripture gives us language for that: “Wretched man that I am! Who will deliver me from this body of death? Thanks be to God through Jesus Christ our Lord!” (Romans 7:24–25). The war is incomplete as long as we fight with “this body of death.” Our ability to achieve total victory over sin will never come in this life. But it will come. It will come because Christ will return.

As Christians we can live in hope — hope that God’s grace is sufficient for our fight against sin, hope that the Spirit is renewing us and restoring our ability to fight sin day by day, and finally, hope that we will one day be completely remade. It is Christ’s ability that is behind each of those hopes. He conquered sin and death to rescue us. He sent his Spirit to redeem us. And he will return again to fully restore us. Our great hope is not in our ability but in Christ’s ability.