The expression "natural man" comes almost entirely from one passage written by Paul. Jesus never used this expression, nor do the original twelve disciples in their teachings.
The phrase appears in 1 Corinthians 2:14. Now the natural man receiveth not the things of the Spirit of God: for they are foolishness unto him; and he cannot know them, because they are spiritually judged. (1 Corinthians 2:14 ASV)
The Greek word translated "natural" is psychikos (ψυχικός). It comes from the word psyche, meaning "soul" or "natural life." It describes a person who lives according to ordinary human nature instead of being led by God's Spirit. The word itself does not mean that a person is incapable of choosing God or responding to Him. Those ideas come from later theological interpretations rather than from the word itself.
The same Greek word appears in the letter of Jude. These are they who make separations, sensual, having not the Spirit. (Jude 19 ASV) Here, "sensual" is the same Greek word, psychikos. Many modern translations render it as "worldly," "natural," or "unspiritual." In both places, the emphasis is on a person's present way of living, not on an unchangeable condition.
Jesus never described people as "natural men." Instead, He used simple language that everyone could understand. He spoke of those who hear His words and obey them, and those who hear His words and refuse to obey. He spoke of good trees and bad trees, sheep and goats, wise builders and foolish builders, and those who love light and those who love darkness. His teaching always places the responsibility on the person's response to God's call.
Jesus invited everyone to come to Him. Come unto me, all ye that labor and are heavy laden, and I will give you rest.(Matthew 11:28 ASV) He also said, If any man willeth to do his will, he shall know of the teaching, whether it is of God. (John 7:17 ASV) Notice that Jesus says, "If anyone is willing." He appeals to the person's willingness to follow God's will.
When speaking to those who rejected Him, Jesus did not say they were unable to come because they were "natural men." Instead, He said, And ye will not come to me, that ye may have life. (John 5:40 ASV) The problem was not that they lacked the ability to respond, but that they refused to do so. Throughout the Gospels, Jesus continually calls people to repent, believe, follow Him, keep His commandments, and remain in His word. These commands assume that people are responsible for how they respond to God's invitation.
The expression "natural man" became much more prominent many centuries later through theological systems that developed after the New Testament was written. During the Protestant Reformation, theologians such as John Calvin built doctrines around this passage, teaching that fallen man is spiritually unable to respond to God unless God first regenerates him. However, this conclusion goes beyond what the expression itself says. The verse states that the natural man does not receive the things of the Spirit because they are spiritually discerned, but it does not explicitly teach that a person is incapable of responding to God's call or of turning to Christ. This is all from Man and not God.
If we allow Jesus' own words to be our primary guide as it should always be, then the expression "natural man" should not become the foundation for understanding salvation. Jesus consistently presents God as calling people, inviting them, warning them, pleading with them, and holding them accountable for their response. He said, For many are called, but few chosen.(Matthew 22:14 ASV) The call is broad, but only those who answer it in faith and obedience become the chosen. Jesus' teaching is centered on God's invitation and man's responsibility to respond. Rather than dividing humanity into fixed categories, He continually urges every person to hear His voice, repent, believe, obey His words, and enter into life.
I have shown verses that clearly express that God does gives us a choice, it is written.