“The spiritual person judges all things, but is himself to be judged by no one” (1 Corinthians 2:15, ESV). This statement is part of a larger context that contrasts the spiritual man with the natural man. In 1 Corinthians 2 and 3, Paul explains that there are four kinds of people: the natural man (1 Corinthians 2:14), the spiritual man (1 Corinthians 2:15), infants in Christ (1 Corinthians 3:1), and the fleshly person (1 Corinthians 3:3).
The natural man will not receive or accept the things of God, because he considers them to be foolishness (1 Corinthians 2:14). While the natural man can have a factual understanding of the words he hears, he can’t judge them accurately because those judgments are spiritual in nature.
In contrast, the spiritual man judges all things (1 Corinthians 2:15). That is, he is able to discern or evaluate properly the things of God because they are spiritually perceived. The ingredient the natural man is missing—and the spiritual man has—is the mind of Christ (1 Corinthians 2:16). The mature believer in Christ is the spiritual man, made alive and possessing a new way of thinking. The spiritual man judges all things because he now has the mind of Christ. The natural man perceives the things of God to be foolishness and refuses to have the thinking of Christ.
Infants in Christ (1 Corinthians 3:1) are those who are newly born again. They have just come to know Christ and are only now beginning to learn about the things of God. Consequently, they might look like a fleshly person at times, not utilizing the mind of Christ in their own thinking. While the infant has been newly born and has a new spirit, he has not yet learned to judge all things or to use the thinking of Christ that now belongs to him.
The fleshly person (1 Corinthians 3:3) often acts like an infant, only without the built-in excuse. Infants are expected to behave like infants because that is what they are. The fleshly person, or carnal person, has not grown as he should have. He should have moved on past infancy and grown to maturity, but his growth has been stunted.
Paul chastises the Corinthians because they are thinking and behaving like fleshly people (1 Corinthians 3:3) when they should be thinking like the spiritual man who judges or discerns all things. They were walking like mere men rather than like those who have the mind of Christ. This immaturity was inexcusable and showed up in their thinking and behavior. They were going beyond what was written in Scripture, becoming arrogant and judging wrongly (1 Corinthians 4:6). They were judging so poorly that they were engaging in appalling immorality, and, instead of mourning, they were arrogant about it (1 Corinthians 5:1–2).
The spiritual man judges all things, but “but is himself to be judged by no one” (1 Corinthians 2:15). In other words, the man with the Spirit of God is able to discern the things of God in a way that the natural (unsaved) man cannot. At the same time, the spiritual person is misunderstood by the natural man. Those without the Spirit cannot appreciate or fully comprehend the spiritual man’s motives, worldview, or character. The spiritual man has the mind or the thinking of Christ, and that is a mystery to those who do not know Christ.
When we believe in Jesus, we are born again and can now think as God has designed us to think. We are no longer natural people whose spirit is not alive. We should move past the immaturities of infancy and press on to maturity. We ought to think and act like spiritual people because that is what we are. As Paul put it elsewhere, we should walk in a manner worthy of our calling (Ephesians 4:1). We should no longer walk like fleshly people, focusing on the desires of our flesh. Rather, we should use the thinking of Christ and grow to maturity, walking in newness of life. As Paul exhorted the Corinthians to do, we ought to demonstrate Christlike judgment and discernment because we have the mind of Christ.