Paul was running into a problem as he preached and revealed the gospel of Christ and the cross of the gospel—immaturity. 

Immaturity (1-4) 

In Paul's definition, a babe in Christ was someone who grasped the gospel, believed, and gave allegiance to Jesus as the new King over a new creation (1), but that allegiance had not brought a change of character to the inner nature (2). The world of lust was still the dominating influence in his or her heart, not King Jesus. Allegiance to the new King had only brought the Corinthian believers back into an introductory relationship with Yahweh, but it was supposed to radically transform the inner person. It was supposed to grow them out of the baby stage of selfishness where they constantly needed nursing on the divine breast milk of “God loves you.” They were supposed to start eating the solid food of learning how to be fully devoted co-workers with Christ.  

Christ’s crucifixion and death leading to followers co-ruling with Him was the solid food the Corinthians had rejected.

They were still worldly in nature—unloving, striving to be better than others, and envious of those who had things others did not. They thought belonging to one leader made them superior to belonging to another. 

They believed but were still driven by lust, not King Jesus (3). When anyone elevates a person, even a good person, over Christ, it is an act of complete immaturity and evidence that a committed follower has not really allowed God in Christ to fully reign (4).

Purpose of Leadership (5-11)

Paul then seeks to define the purpose of leadership under the rule of Jesus, hoping he can show the Corinthians just how foolish their making celebrities of men could be. Paul answers the question: who are God's leaders? They are people assigned roles in the church—some are assigned planting roles, others watering roles—all are servants of the growth God had promised to give (5-7).

Paul is developing his first metaphor for this chapter of planting and watering.

Planting and watering had one goal: to grow what God had designed to grow. While each received a personal reward, their individual job had the same purpose (8). Paul here adds another metaphor—building. What was being built also belonged to God. What was being planted belonged to God. The community of people who gave their allegiance to Christ and then joined with Christ in bringing the whole world back under God, belonged to God. This field and building belonged to God alone, no one else. 

Leaders were merely God's co-workers, planting God's field and building God's building of fully devoted followers of King Jesus (9).

Paul's calling was to lay the foundation for what God was building. Paul was working as a skilled master builder, knowing another would come along later and build on what he had started (10).

Paul then encourages the church not to be confused. The foundation Paul had been laying was not the foundation he had chosen; actually, the foundation he had laid had already been laid in the Spirit. Paul was making it vividly clear that the foundation was the Kingship of Jesus Christ (11). This foundation talk is another metaphor. This metaphor of foundation and building was common to Paul's thinking as he thought about what Jesus had meant when He said His body was a temple (John 2:19-22). Paul developed Jesus' metaphor to include describing Christ's universal body of believers as a temple (Ephesians 2:21).

What Leaders Build on the Foundation (12-13) 

Paul then expands his metaphor by letting it be known that what the Corinthian leaders built on the foundation could be material of enduring quality, or one could build on the foundation with materials of temporary quality, easily consumed by some kind of fiery testing. This was meant to concern the reader that it is possible to build on the foundation of Christ with materials that would not endure the fire of judgment (12-13).

The Judgment (14-15)

Here Paul saw the work of the leaders being judged on the day when the true nature of everything is exposed. Some assert that Paul was defining the day of Christ's judgment. 

Leaders who build on leading people to full allegiance in Christ will find that those materials will withstand any fire and the leader will be rewarded (14). If a leader builds on less-than-outright devotion to Christ, he might be saved, but it is going to be like a fireman running in at the last minute and dragging the leader to safety with fire raging all around (15).

Don't You Know? (16-17)

“Don’t you yourselves know” is the first use of this phrase, with nine others to follow (5:6; 6:2-3,9,15-16, 19; 9:13,24). Every time Paul used this phrase, he introduced an absolute truth in this letter. He asserted that those believers who had given their full allegiance to Christ were God's sanctuary on Earth, and the Spirit of God lived within them as a people (16). If anyone sought to destroy God's home on Earth by seeking to build with materials that did not last, they would be destroyed themselves. It was one thing to ignorantly co-build with Christ and to build with inferior material. To build so on purpose would result in a completely different result for those builders. God's house belongs to Him and His Kingdom. Those who form His house have no say in the materials used to form it or what the building grows into. Their purpose is to build with God's finest materials of complete and total devotion to Christ (17).

Paul Rebukes the Leaders (18-23)

Obviously, there had been some leaders at Corinth who were taking their eyes off of Jesus and elevating other leaders in the body of Christ as being more right than others. Among the Corinthians, there were contrasting opinions as to the superiority of different leaders’ opinions.

Paul announces the bunch of them were becoming self-deceived, thinking the world's way, imagining one apostle and those belonging to that one apostle superior to others belonging to another apostle. 

Sounding wise and insightful was not how God grew His building. The whole group of them needed to return their focus to Jesus. They needed to become fools by the world's standards and become wise by God's standards. This would be like asking a Greek to commit social suicide (18).

Paul then quotes Job 5:13, announcing that those who thought themselves wise by claiming a point of view superior to another would become ensnared and trapped and exposed for just how foolish they were (19).

Then Paul quotes Psalm 94:11, stating that Yahweh knows just how worthless human wisdom can be, and in the end, because human thinking is faulty, it would be discovered foolish (20).

Because the foolish would be found to be utterly foolish, Paul calls for the Corinthians to put a stop to this destructive habit of making one man, at any level, superior to another (21). Every leader was a gift from God and belonged to every other Corinthian believer. Not only that but every encounter and experience in life belonged to every Corinthian believer. Such is the nature of Jesus' reign on Earth; He is able to make everything work in His followers' favor (22).

This was all true because the entire church, everyone who had given their allegiance to King Jesus, belonged to Jesus, and King Jesus belonged to God, meaning they belonged to God (23).