The title reveals a difference of the human state that by nature is both spiritual and carnal beings. The spiritual side of man sees God and accepts him into his or her life but the carnal man sees life through the flesh and cannot accept God. The difference is the perspective of the individual, as the spiritual man knows that God exists and has a plan for their life. The Carnal man does not have an interest in God whatsoever.
The Spiritual nature and the Carnal nature refer to the way men and women think. When God refers to the spiritual of carnal nature he is speaking to the depth and basic orientation of the mind. For example the referring to the carnal mind God said,
The Lord saw how great man's wickedness on the earth had become, and that every inclination of the thoughts of his heart was only evil all the time. The Lord was grieved that he had made man on the earth, and his heart was filled with pain. Genesis 6:5-6
God saw the intent of the heart was evil and was grieved. Yet man was born into the kingdom of God with a mind involved with a temporary but corrupted world. The world has suppressed the truth and for this reason men are not always aware of its influence on us as a Christian. As Christians we are no longer of this world but have our citizenship recorded in heaven. It also stands to reason that being citizens of heaven that we need to think as one.
It may be for this reason that Paul places a demand on Christians in Romans 12:2 to renew their mind as a reasonable act of spiritual worship. Renewing the mind affects our relationship to God and who we are, but it rebuilds the thinking patterns so we can think and understand the desires of God. Understanding God can only be known through spiritual discernment and that means we need the help of the Holy Spirit to guide us. Renewing the mind constructs a disciplined mind that brings our thoughts into agreement with the word of God.
Although we are pilgrims in this world we are citizens of heaven traveling on their way home. And because we are alien to this world we should think and act as citizens of heaven. By the same token the world should see us as different like we are from another place or country.
A prudent man known by God would search the bible to know facts with certainty and be able to test and approve God's good and perfect will. We have to ask this question. Have we placed God into a position where he can say – “I didn’t say that” or “that’s not what I intended”. This concept should give all the more reason to know the good and perfect will of God with certainty.
The disciples were prepared for Jesus to reinstate Israel to its former state and send the Romans packing. On the other hand, Jesus frequently prepared his disciples for his death telling them that he would be killed and three days later rise again. Thinking as a man Peter took Jesus aside to set him straight. However, Jesus rebuked Peter.
"Get behind me, Satan!" he said. "You do not have in mind the things of God, but the things of men." Mark 8:33
Peter made unwarranted presumptions about Jesus in a worldly or carnal fashion. Peter had his own opinion and treated his opinions as fact. Jesus was going to fulfill the plans that Peter assumed Jesus would do. Peter did not have the mind of Christ or consider the plans that God had, he became boldly arrogant and offensive to Christ.
When the Pharisees were challenged the authority of Jesus Christ after he had taken a whip into the temple courts to cleanse the temple. Replying to the Pharisees, Jesus said.
My testimony is valid, for I know where I came from and where I am going. But you have no idea where I come from or where I am going. You judge by human standards; I pass judgment on no one. John 8:14-16
Paul continues that theme when he said,
The spiritual man makes judgments about all things, but he himself is not subject to any man's judgment: "For who has known the mind of the Lord that he may instruct him?" But we have the mind of Christ. 1 Corinthians 2:15-16
Since, then, you have been raised with Christ, set your hearts on things above, where Christ is seated at the right hand of God. Set your minds on things above, not on earthly things. Colossians 3:1-2
Renewing our mind to know and approve God’s will affect your life. The process of renewing the mind takes a lifetime because you are laying a new foundation of thought to make decisions from. And renewing our mind is a must because we live in a world that suppresses the truth and neither concerned for truth or in God.
We know that the law is spiritual; but I am unspiritual, sold as a slave to sin. I do not understand what I do. For what I want to do I do not do, but what I hate I do. Romans 7:14-15
He said there was a war going on in his mind and the way to overcome a sinful life was to set his mind on what the spirit desired. Paul wasn’t speaking of a casual effort to renew our mind but a focused effort. A man is a Jew if he is one inwardly (Romans 2:29) by the same reason a man is only a Christian if he thinks like God.
Those who live according to the sinful nature have their minds set on what that nature desires; but those who live in accordance with the Spirit have their minds set on what the Spirit desires. Romans 8:5
The carnal mind sets his mind on his evil desires and the spiritual man disciplines his mind to think as God does. The carnal mind is arrogant, proud, demonstrates superiority and mocks other people’s lifestyle. They should remember that their day will come.
The eyes of the arrogant man will be humbled and the pride of men brought low; the Lord alone will be exalted in that day. Isaiah 2:11