3 Men by Frederick K. C. Price explains that Scripture categorizes humanity spiritually as the natural man, who cannot understand spiritual truth (1 Corinthians 2:14), the carnal man, a believer still ruled by the flesh (1 Corinthians 3:1–3), and the spiritual man, who matures through the Word and the Holy Spirit (1 Corinthians 2:15; Romans 12:2). The teaching highlights how each stage reflects a person’s growth and responsiveness to God.