write the main idea of the paragraph below.
According to Paul in I Corinthians 2:14-16 and 3:1, people are divided into three classes: natural man (unbelievers), spiritual man, and carnal man (believers). Natural man is negative to God and His Word. He is body and soul. His human spirit has not been "born again." The word "natural" means "soulish" when translated literally from the Greek. He will not accept or receive the things of God; they are foolishness to him. There is no way he can understand the Word because the Holy Spirit interprets it to those who are indwelt by Him. The spiritual man and the carnal man are both believers; they have believed on the Lord Jesus Christ and become part of the "household of God." But they are different. The spiritual man by his own choice is positive to God and His Word; the Holy Spirit is in control of his life. He studies the Word, and he is able to evaluate everything about him from God's standpoint. Others simply cannot understand what makes him tick. He has the "mind of Christ," because he is a student of the Word. The carnal man, although he is a child of God, is a disobedient child. He is a "babe in Christ" and has been for many years. He has no desire to learn from the Word. He is still having trouble with pablum and milk when he gets it; the meat of the Word gives him indigestion. Paul says he is "at enmity with God." His sin nature is in charge of his life, not the Holy Spirit. God disciplines him, for God is a faithful father.