Jeremiah 8:8 “How can you say, ‘We are wise, And the law of the LORD is with us’? But behold, the lying pen of the scribes has made it into a lie. 11 “They heal the brokenness of the daughter of My people superficially, Saying, ‘Peace, peace,’ But there is no peace.
Genesis 3:5 “For God knows that in the day you eat from it your eyes will be opened, and you will be like God, knowing good and evil.”
Matthew 18:1 At that time the disciples came to Jesus and said, “Who then is greatest in the kingdom of heaven?” 2 And He called a child to Himself and set him before them, 3 and said, “Truly I say to you, unless you are converted and become like children, you will not enter the kingdom of heaven. 4 “Whoever then humbles himself as this child, he is the greatest in the kingdom of heaven.
In some way conversion to Christ must be the opposite in some way to the fall. Conversion would be a returning to the image of God (a fuller way) which was lost (though not absolutely and completely) in the fall. We can see this teaching in Ephesians 4: “that, in reference to your former manner of life, you lay aside the old self, which is being corrupted in accordance with the lusts of deceit, 23 and that you be renewed in the spirit of your mind, 24 and put on the new self, which in the likeness of God has been created in righteousness and holiness of the truth.” The old self, which is what man has from the fall, is always being corrupted with the lusts of deceit. There again we see that the old man lives in accordance with deception, and that deception is carried out because of his lusts. But the new self is created in righteousness and holiness of the truth.
The historical teaching is that man lost the moral image of God which would include love for God in holiness and truth, but man did not lose the rational nature and ability of choice that God gave him. But since man lost the moral image of God, the natural image of God is used in the pursuit of sin. For man to glorify God, therefore, man must have or be recreated in the image of God in the sense that the moral nature of God must be regained. In the fall man became like God in a wicked way in that man now wanted to be like God and in fact to be his own god. In the new creation (new birth) man repents from the pride of being his own god to become like God in his moral nature which is to do all out of love to God and for His glory.
The old man can become very religious and yet do nothing but serve the old self. The old man, which is man wanting to be his own god, can live in stringent external morality and religious devotion and yet all of that be nothing but pride and the honor and glory of self. In all of the moral and religious actions of the unregenerate man there is nothing but pride and self. True Christianity stands opposed to the natural man at all points and all ways in terms of the natural man being a true Christian. A person must be born again to enter the kingdom which means that a person must be given repentance from the old man and granted a renewing work (new creation) of God so that he may become a new man which is to have a moral nature or a moral life which is lived out of love for God and His glory.
The passage in Matthew 18 can be looked at by a natural man as a way of working for salvation. That man will think that this conversion and becoming like a child in humility is his own works and that he can strive for that and even obtain that in his own strength. The spiritual man will look at Matthew 18 and see the glory of the work of God in salvation. The spiritual man will see the grace of God in overcoming the old nature and the grace of God in giving man a new heart and a new life. The natural man will look at a passage like Matthew 18:1-4 and Ephesians 4:22-24 and see those as teaching him how he is to work at casting off the old nature and putting on the new. The spiritual man looks at those passages and sees the glory of God’s grace in doing those works.
The fall brought man into pride and self. The work of Christ grants man a repentance from pride and self and then to the kingdom of Christ in man. There is a huge difference between the natural man and the spiritual man, though the natural man may not be able to see it because he is so focused on the external things. A very religious man who is still a natural man may appear better in the externals than some spiritual men, but on the inside the natural man is like the devil while the spiritual man is like Christ and has Christ. The natural man will do all he does by the strength of self and pride while the spiritual man will do what he does by the power of the Spirit and what he does is from Christ.
The greatest in the eyes of the world is a very proud man, but the greatest in the kingdom is a humble man. The proud man is full of self and does all for self, yet the humble man is full of Christ and does all for Christ. It is true that the spiritual man is far from perfect and sees much of pride and self in him, but the natural man has nothing but pride and self (like the devil) in him. For a man to be humbled and to enter the kingdom is salvation from the devil, sin, and pride/self. It must be a work of God for pride will never truly repent of pride, though it may in the appearance of it. Salvation must be a work of God because the natural man cannot repent of self because that would be self repenting of self and that cannot be done. Salvation is a glorious work of God in restoring His image in the souls of His people. It is not simply a choice of man, but it is a work of the living God.