Galatians 5:16-18 is used by many to prove they have two natures. They say "the flesh" is the sin nature, and the Spirit is the new nature. But these scriptures do not say this. The passage only says that these two, the flesh and the Spirit, are in opposition to one another.
The flesh and the Spirit are only in opposition to one another when a person is under the law. The law brings bondage, but the Spirit brings freedom. Verse 24 tells us, "Those who belong to Christ Jesus have crucified the flesh with its passions and desires." If the flesh is the old man or sin nature, it has been crucified--and that means death. But the flesh is not the sin nature; it is only the instrument that has been used by sin. Paul says he was sold into bondage to sin. Man has only one nature--a human nature. When he has faith that brings him into life, and is cleansed from all sin, that which made him sin is changed through the new birth. Man was a wrong being, and now that he has been born again, he is brought back into proper relationship and fellowship with God.
Man does not need a "sin nature" to be able to sin. Adam sinned and did not have a sin nature. It is possible for Christians to sin without having a sin nature. They can be drawn out of their abiding place in Christ. If their relationship is as it should be, they are finding fulfillment in Christ, not in their own desires. If we are properly related to the Lord, we will be properly related to other people and things. But we can never let this mean that our desires and imaginations, minds and wills are not set aside for God's use only. They must be disciplined by the Spirit as we are exercised to discern good and evil. There must be a working out of what God has worked in us.
Paul's words in Romans 7 and Galatians 5 can never be taken to mean that we have two natures. In Romans 8 and in Galatians 5:18 we read words to this effect: "If you are led by the Spirit, you are not under the law." When you are under the law, you may not do the things you please. Romans 7 tells us that Paul wanted to do good, but could not. But Romans 8:2 tells us, "The law of the Spirit of life in Christ Jesus has set us free from the law of sin and of death."
If Christians are going to rightly understand the seventh chapter of Romans, God must reveal to them whether this was Paul's experience as a Christian or the experience of his past life under the law. This passage has been one of the problem texts pertaining to the two nature theory. One reason for wrong understanding is that man is trying to justify his experience, rather than allowing the Word of God to change him. The attitude we see today should cause us concern. Christians are trying to make room for sin in their lives, rather than looking for a way to be free from sin and thus please God as they walk in faith.
In this time we have too much natural thinking and man-made theology. We need to get back to God's way and His working. The reason there is so little holiness today is that there is so little understanding of what God is doing and how He is doing it in us. We will never understand God's ways if we do not have a personal relationship with Him. Out of this relationship comes the power to be sons of God and live in His life. Faith brings us into a vital experience of His life. We are not talking about the "eradification" or "identification" theories. We are speaking about what happens at new birth. That which is born out of the Spirit is spirit. We came into the world at one time in a human body through natural birth. Now if we are going to have eternal life, we must be born again--not born again in the flesh, but born again of the Spirit. God's plan is perfect. He knows what we need to be made like Him. First we need to be made alive spiritually, and then we need to live His life by faith--not our life, which is governed by selfishness or our own passions and desires.
Paul's desire for the believers was that "God sanctify you entirely. And may your spirit and soul and body be preserved complete, without blame at the coming of our Lord Jesus Christ" (I Thessalonians 5:23). Was this only wishful thinking on Paul's part? Paul understood God's plan and His working, and if we will seek the kingdom of God and His righteousness, Jesus will become our wisdom and knowledge. Only when we create a salvation that is separate from our relationship with Christ do we get into all these theories, which can never transform us into His image or bring us into full growth in Christ. God leaves no place for sin or a sin nature in His new creation.
I Peter 2:24 says, "He himself bore our sins in His body on the cross, that we might die to sin and live to righteousness." Those who hold to the two nature theory must see there was nothing God could do to cause the old creation to fulfill His purpose. There had to be a new creation. Jesus said that you cannot put new wine in old wineskins, or both will be lost. We are a new creation in Christ Jesus. There is no place for any of the old in the new. We just need to "sanctify Christ as Lord in our hearts" (I Peter 3:15).
A proper understanding of law and grace would throw light on this area of our walk in Christ. Many say they are free, but they continue to battle, flesh against Spirit, because they are under the law. But Romans 7 says we died in Christ to the law, that we might be free to be joined to another. The law was our tutor to lead us to Christ, that we now may be justified by faith. Paul says we now are more than conquerors in Christ Jesus.
Paul tells us in Galatians 1:11 that the gospel he preaches is not according to man. He goes further in II Corinthian 7:1, and tells us to cleanse ourselves from all that can defile flesh or spirit, and in the fear of God to complete our consecration. This would not be possible if we had two natures. Paul further says in II Corinthians 6:16, "What agreement has the temple of God with idols? For we are the temple of the living God!" How can this be possible in reality if what many say (that they still have a sin nature) is true? What contradiction and belittling of this great salvation!