I am writing a series of articles concerning a Christian’s “union with Christ” and attempting to answer a few common questions. I have previously written on the definition of union with Christ.

Let’s review for a moment. Every human being is a sinner and separated from God because of the “federal headship” of Adam. Adam was acting as our representative in the garden, so when he sinned against God in Genesis 3 by eating of the forbidden fruit, it is as if we all consumed the fruit in disobedience (Romans 5:12).  Therefore, we are conceived and born into this world with a sinful nature and are by that nature “children of wrath” (Ephesians 2:3).   That is horrific news.

But there is another who also serves as our federal representative – the second Adam – who is greater and better than the first. This second Adam is, of course, Jesus Christ, and when we acknowledge him as the Lord of our life through faith, his actions are credited to us as if we were the ones who carried them out. When Jesus perfectly kept the law, we perfectly kept the law. When Jesus was crucified, we were crucified. When Jesus rose from the dead, we too will rise from the dead.  And so forth.

That is what it means in Galatians 2:20 when it says, “I have been crucified with Christ…” Our old, sinful nature was crucified right along with Christ and we are now new creations in Jesus. We are seen as righteous by God because of our union with Christ – the perfection of Jesus has been imputed to us through faith. That is incredibly good news.

But a very good question comes out of this very good news. If Christ’s righteousness has been imputed to us and our sinful nature has been crucified, why do we still struggle with sin? For many Christians, the reality of sin lingering in their lives creates strong doubts as to the validity of their salvation experience. Shouldn’t we be sinless now that we are new creations?

The most common response to this question points to the ongoing struggle between what is perceived to be two natures of a Christian’s life – the sinful nature and the new nature in Christ. We are physically born with a sin nature in Adam and we are spiritually born with a new nature in Christ. Thus, these two natures are in constant conflict with one another. This makes the answer to the question fairly simple – Christians sin when they let their sinful nature take precedence over their new nature.

But I am not satisfied with that response. The breathtaking claims of the gospel demonstrate how the two conflicting natures solution limits the transforming power of Christ. I believe the Scriptures teach a gospel so radical and so powerful that it does not simply bring an additional new nature alongside the old nature to combat it, but rather the gospel puts to death our old nature once and for all, leaving us with a single new nature in Christ.

Consider the language of dying to the old nature when we are in Christ:

“For you have died, and your life is hidden with Christ in God.” (Colossians 3:3)
“We know that our old self was crucified with him in order that the body of sin might be brought to nothing, so that we would no longer be enslaved to sin.” (Romans 6:6)
“Therefore, if anyone is in Christ he is a new creation, the old is passed away; behold, the new has come.” (2nd Corinthians 5:17)
“I have been crucified with Christ. It is no longer I who live, but Christ who lives in me…” (Galatians 2:20)

When Paul says that he has died and that the old nature has “passed away,” he is referring to the sinful nature in Adam. If we are to believe that Adam’s sin nature is still alive and well in the life of a believer, then what does Paul mean when he emphatically announces the death of his old nature? These verses would lose their meaning and their power.

When we then consider the language of the New Testament as it encourages a new believer, this makes even more sense. The New Testament does not instruct a believer to wage war against their own personal sinful nature because Christ has already waged that war and has claimed the victory. In his commentary on Romans, Martyn Lloyd-Jones said, “We are never called to crucify our old man. Why? Because it has already happened – the old man was crucified with Christ on the cross. Nowhere does the Scripture call upon you to crucify your old man for the obvious reason that he has already gone.”

Now, let me address one significant push-back. Someone might say, well what about the verses where Paul instructs us to stop living according to the flesh? Isn’t “the flesh” just another way of saying our old nature? For example, Galatians 5:16 says, “But I say, walk by the Spirit, and you will not gratify the desires of the flesh.” And Romans 7:25 says, “I myself serve the law of God with my mind, but with my flesh I serve the law of sin.” So, doesn’t this negate the points I made above? Isn’t our old nature still alive since we can “serve the law of sin” in our flesh?

No, our tendency to satisfy the flesh does not mean we have two conflicting natures dwelling in us. Instead, it means the self-gratifying patterns and memories of our old nature can entice us to think and act and speak in ways that are in opposition to our new nature. Paul acknowledges the reality of those desires while maintaining the one-nature promise of the gospel. Look again at Paul’s instructions to the Romans – right after Paul admits that he is prone to walk according to the flesh, he reminds us in Romans 8:9 that “You, however, are not in the flesh but in the Spirit, if in fact the Spirit of God dwells in you.” In other words, we are not “in” two competing natures, but we must depend on Christ to renew our minds to the reality of our new identity in order to avoid being lured by the desires of worldly actions. That is why Paul says in Romans 12:2, “Do not be conformed to this world, but be transformed by the renewal of your mind, that by testing you may discern what is the will of God, what is good and acceptable and perfect.” And also in Romans 8:5, “For those who live according to the flesh set their minds on the things of the flesh, but those who live according to the Spirit set their minds on the things of the Spirit.”

Do you see it? The battle before us every day is not an attempt to kill the old nature; Christ has already done that. Our battle is to renew, to remember, to set our minds on who we are in Christ Jesus – that he has completely redeemed us from the curse of sin and has imputed to us his righteousness. That in Christ, we have all the power we need to do all that he requires, including avoiding the patterns of the flesh. That is why it is essential to preach the gospel to ourselves every day, for the beauty of that message keeps us from despair.

Another way to think about our old nature is to consider how we were once under the “dominion” of sin. When we were still bound to our old nature in Adam, we were hopelessly under the reign of sin. But in Christ, sin no longer has dominion. Pauls says, ” For sin will have no dominion over you, since you are not under law but under grace.” (Romans 6:14). If we had two conflicting natures in us, we would still be under partial dominion since the old nature would still be alive. But the message of the gospel is clear; we are no longer slaves to sin. We will certainly sin, but it does not have dominion over us due to our new nature in Christ.

You might think, well so what? If we are still in combat with the flesh and are prone to wander, what does it matter if it is an old sin nature or patterns of the flesh? Perhaps you think it is a distinction without a difference.

I believe the difference is significant. First, at a minimum, we want to understand what God has to say about our new identity in Christ. If, in fact, we have only one new nature in Christ and not two competing natures, that is important because it is the way God is accomplishing his purposes of redemption. But second, there is freedom in knowing we are no longer enslaved to sin because we are no longer bound by a sinful nature. When a Christian begins to understand the full implications of their new nature in Jesus Christ, they will become more confident of the power available to them to live a joyful, obedient, purposeful life.

So, Christians will continue to sin because we still have corruptible bodies that are prone to fleshly patterns and desires. We have already received the full righteousness of Christ for salvation, but we have not yet put on a glorified body immune to the desires of the flesh. However, we are no longer enslaved by the dominion of sin in our lives because the old nature was crucified with Jesus and we have now enjoy the freedom and power of his presence in us.

I will end with Martin Lloyd-Jones once again as he explains why the one nature truth is so important:

“…you are in Christ. If we but saw this as we should, we would really begin to live as Christians. We would all hold up our heads, we would defy sin and Satan, and we would rejoice in Christ as we ought.”