In 1 Corinthians 2 Paul uses the phrase "natural man" or "natural person" in contradistinction to the "spiritual man." The "natural man" is a human apart from Christ whereas the "spiritual man" is the person who has been saved in Jesus and has the indwelling Holy Spirit.
What does Paul mean when he writes of the natural man?
Paul uses a similar concept in Romans 7, Ephesians 4, and Colossians 3 when he contrasts the "old self" with the "new self." In those epistles, Paul is referring to a person who has the indwelling Holy Spirit and is struggling against the natural desires of our human flesh. All those in Christ are new creations (2 Corinthians 5:17), but transformation is a process and our "new selves" struggle against the fleshly desires of our "old selves." In 1 Corinthians 2, Paul is not so much distinguishing between our internal struggle as believers so much as he is contrasting those apart from Christ and those in Christ.
In 1 Corinthians 2, Paul writes about both the wisdom of God and the wisdom of people. He writes that the wisdom of people cannot capture the wisdom of God. God's wisdom is only available through God. "No one comprehends the thoughts of God except the Spirit of God. Now we have received not the spirit of the world, but the Spirit who is from God, that we might understand the things freely given us by God" (1 Corinthians 2:11–12). Paul goes on to say that the "natural person" cannot accept the things of God because they can only be discerned through the lens of a person's spirit (1 Corinthians 2:14). It is the Holy Spirit who illumines our hearts and minds to the truth of God.
The natural person concerns himself with the perishable things (Matthew 6:25–33) of this world (our bodies, possessions, status, wealth, etc.). A person in a relationship with God through Jesus Christ (John 16:7–11) increasingly concerns himself with the things of the Spirit (eternity, bringing God's kingdom to earth, sharing the gospel). In Christ, we gain spiritual perspective and understanding that we did not have apart from Him.
A spiritual person, per the Bible, is one with the indwelling Holy Spirit—a person who has put his faith in Jesus. All people are separated from God because of the introduction of sin by Adam and Eve plus their own imperfection and rebellion against God (Romans 3:23; 5:12–21). However, God sent Jesus so that each person may accept Him and have an eternal relationship with God (John 3:16–18).
Once a person becomes a Christian, he is transformed (2 Corinthians 5:17; Romans 8:1). First Corinthians 15:21–22 tells us, "For as by a man came death, by a man has come also the resurrection of the dead. For as in Adam all die, so also in Christ shall all be made alive" (1 Corinthians 15:21–22). The Christian life is far from a "natural" one; rather, it is a life led by the very Spirit of God.
What does the Bible mean when it talks about the flesh?
What is human nature?
What is the inner man?
Who are we in Christ?
Why did God create humanity?
Truth about Humanity