The Lord Jesus Christ said to Nicodemus, "Ye must be born again" (John 3:7). Today there are many people that think of the new birth as a kind of change that takes place in one's life, or what they call a "Christian experience." But when the Bible talks about new birth it is because God actually gives a new life to the one who believes on the Lord Jesus. It is not an improvement of the old one, but a new one—born from above. Of course a change will result, because the new life wants to please God.
Trusting, Not Teaching
Nicodemus came to the Lord with the thought that he would get some teaching. Indeed the Lord Jesus is and was a wonderful teacher, but what the sinner needs first of all is to receive a new life, and so the Lord replied, "Except a man be born again, he cannot see the kingdom of God." (John 3:3). Man had teaching under the law, for "the law is holy … just and good" (Romans 7:12). All those commandments and precepts laid down for man in the Old Testament were from God. But they did not give a new life, for the Scripture says, "If there had been a law given which could have given life, verily righteousness should have been by the law" (Galatians 3:21).
Why then did God give the law? Many people do not believe that "The heart is deceitful above all things, and desperately wicked" (Jeremiah 17:9). If I have a child and there is a heavy suitcase which he thinks he can carry, how can I prove to him that he cannot? Just give him a chance to try. God did just that when He gave His commandments, and we have all failed miserably to keep them.
Rebirth, not Reform
What the Lord is showing here in John 3 is that salvation does not come by being reformed—it comes by being reborn. There has been a work of God for us at Calvary's cross when Jesus died for our sins and rose again, but there has to be something wrought inside us because the natural heart of man will never respond to God. God uses His precious Word applied by the power of the Spirit to accomplish this. "Seeing ye have purified your souls in obeying the truth through the Spirit…. Being born again … by the Word of God, which liveth and abideth for ever" (1 Peter 1:22,23). When we see our need of Christ, repent, and trust in Him, we are born again and receive a new life from God. That is why the believer desires different things. God has given the believer a new life, the "new man" that wants to please Him.
What About the Old Nature?
When someone is born again, what happens to the old nature? God does not improve it. He forgives our sins, but the nature that causes us to sin will remain with us as long as we are in this body. Even if one has been saved for fifty years, the fallen nature has not improved one bit, and it never will.
In Romans 6 we are told about what God has done in connection with our old nature, and what we are to do with it as well. This old nature is sometimes called "the flesh," "the old man," "sin," or "sin in the flesh." In verse 6 we are told "Our old man is crucified with Him." At the cross of Calvary, the Lord Jesus not only bore my sins, but His death was the end of my standing before Him as a child of Adam. God no longer sees the believer as a child of fallen Adam, for we have died out of that position and entered a new position before Him by the resurrection of the Lord Jesus (Romans 6:9-11).
Out With the Old, In With the New
Oh, you say, sometimes I want to do what is wrong! Now it is not the new life that wants to act that way—it is because you're allowing the "old man" to be active. Romans 6:11 says, "Reckon ye also yourselves to be dead indeed unto sin, but alive unto God through Jesus Christ our Lord." When temptation is presented to us we can turn from those bad thoughts and allow the Spirit of God through the "new man" to occupy us with Christ. The new man finds its joy and deliverance in looking away from self to Christ.
Let me use an illustration to help make this point clear. Let us suppose I plan to build something, and I have a pile of lumber which I have been saving for this purpose. I decide to hire a carpenter to build it for me, and I ask him to please use this lumber for the building. He goes out to look at the lumber and after a while he comes back saying, "I have looked over your pile of lumber and I have some bad news for you. Your lumber is all rotten. There is not one good piece in the whole pile." What did he do? He did not try to improve it, or use part of it. No! He condemned it. This is what God has done with our old nature, and what we should do, too.
My carpenter condemned my pile of lumber, but then he said, "I have some good news for you. I have brought you all the new lumber you need, and it will not cost you anything. It is a gift." It is indeed a sad discovery to find out how very bad the old nature really is, but this should only lead us to be more thankful for deliverance, knowing that our new standing before God is because of that blessed work accomplished for us at Calvary. Dear born-again believer, never forget that God sees you "in Christ Jesus" and "holy and without blame before Him in love" (Ephesians 1:4). How great is that!
Are you, dear reader, looking for something good in the old nature? God gave it up long ago, and if you give it up now you will be a happy person. Allow the Great Carpenter to throw a tarp over the pile of rotten lumber. It will not improve while under there, but he says just to consider it is not there. That is what it is to "reckon yourselves to be dead indeed to sin." When some bad thought comes into your mind, how are you going to be set free? If you allow the Spirit of God through the new man to occupy you with Christ, you will be set free.
Feeding the New Nature
It is vitally important that we read God's Word and pray. If we neglect this, the enemy knows our weak points and he will come and work on that "old man" to lead us into sin. A true believer can never be lost, but he can, like David of old, lose the joy of God's salvation and dishonor his Lord. The prayer of the Psalmist is good for us all: "Cleanse Thou me from secret faults. Keep back Thy servant also from presumptuous sins; let them not have dominion over me: then shall I be upright, and I shall be innocent from the great transgression. Let the words of my mouth, and the meditation of my heart, be acceptable in Thy sight, O Lord, my strength, and my redeemer" (Psalm 19:12-14).
—Condensed from Two Natures in the Believer by G.H. Hayhoe.