Now, two natures emerge in a believer. One is the sinful nature, the flesh, which is the nature of old Adam. The other is the spiritual life, the "new spirit," which bears God's nature. Brothers, you have believed in the Lord Jesus, and you know that you are saved. For this reason, you are regenerated already. You should now know that there are two natures within you. These two natures are the cause of your numerous conflicts. The reason you fluctuate up and down and alternate between victory and defeat is that two natures are exercising their influence over you. These two natures are the key to the riddle of your life of struggling.

For a young believer to have such experiences of inward conflict and condemnation proves that he is regenerated. An unregenerated person is still dead in sin. Although he may at times be condemned in his conscience, such feeling is very ill-defined. Without the new nature, it is obvious that a person will not experience the conflict between the new nature and the old.

The Bible clearly describes this conflict between the new nature and the old. In Romans 7, Paul vividly portrayed this kind of life of conflict through his own experience. He said, "For what I work out, I do not acknowledge; for what I will, this I do not practice; but what I hate, this I do" (v. 15). This is the conflict of the new and the old natures. The description here is that of the experience of a newborn believer. At such times, he is still a babe in Christ. He is in the infancy of his spiritual life, and he is still childish and powerless. The "I" in the "what I will" and "what I hate" refers to the new nature. Although the new nature desires God's will and hates sin, the other nature, the old nature, is too strong. This, together with the weakness of a person's will, compels that one to sin. However, the new nature does not sin. "Now then it is no longer I that work it out, but sin that dwells in me" (v. 17). The first "I" is the "I" of the new nature. "Sin" is another name for the sinful nature. Therefore, this verse means that the one who sins is not the new "I," but the sinful nature. Of course, this does not remove man's responsibility. Paul went on to describe the positive contradiction between the old and the new natures, that is, the contradiction between the sinful nature and the spiritual life.

"For I know that in me, that is, in my flesh, nothing good dwells; for to will is present with me, but to work out the good is not. For I do not do the good which I will; but the evil which I do not will, this I practice...I find then the law with me who wills to do the good, that is, the evil is present with me. For I delight in the law of God according to the inner man, but I see a different law in my members, warring against the law of my mind and making me a captive to the law of sin which is in my members" (Rom. 7:18-23). This is indeed the common experience of all believers: to will to do good, yet be unable to do it, and to will to oppose evil, yet be unable to reject it. When temptation comes, a power (the "law") suppresses our desire for holiness. As a result, we speak what we ought not speak and do what we ought not do. Despite many resolutions and vows, we are unable to stop this power from working.

In Galatians Paul described again the conflict between these two natures. "For the flesh lusts against the Spirit, and the Spirit against the flesh; for these oppose each other that you would not do the things that you desire" (5:17). The old nature and the new nature are enemies of each other. Both strive to gain absolute supremacy over us. The old nature has its desires and its power, and the new nature has its also. The two natures exist in us simultaneously. Hence, there is the constant conflict. They are like Esau and Jacob in the womb of Rebekah; the two were diametrically opposed to each other, and at times they fought with each other in the womb. When the Son of God was on earth, all the powers on earth plotted to kill Him. In the same way, while the Son of God lives in our heart as our new life, all the lusts in our flesh strive to remove Him.

Before we go on, we should first understand the characteristics of the two natures. The old nature was born of our flesh. In it, "nothing good dwells" (Rom. 7:18). The new nature is from God. It "cannot sin" (1 John 3:9). The new and the old natures are completely different. Not only do they come from different sources; even their functions are different. However, both exist in the believers. The old nature is the flesh. "And those who are in the flesh cannot please God" (Rom. 8:8). The new nature is the new spirit. "God is Spirit, and those who worship Him must worship in spirit and reality." Without comparison with the new nature, the old nature, humanly speaking, is not too bad, despite some self-excusing inclinations and lusts. Yet, when a person is regenerated, the new nature comes in with the new life. When both the new and the old natures are put side by side, the true characteristics of the old nature are exposed.