A wrong self perception can lead to disaster. The Corinthians thought they were mature, but Paul says they are infants.
1. God's servants - leaders are servants of the Church. (v1-5). Divisions caused by following a certain leader. Note the question 'what are these leaders' - their role is what is important - they are servants. Each has a different task (v6-9). They are not in competition - co-workers (v9). The leaders were united in the task of serving Christ. God causes the growth.
2. God's service - Farming and Construction. (v10-11). One foundation, and one message. The Gospel is both the 'milk' and the 'solid food' and is our only message. What are the materials (v12-15)? This is not about Salvation or Salvation by works. Paul is talking about 'workmanship' - the quality and cost of our work regardless of what it may be (Col 1:28ff - note word 'struggling'). It affects our 'praise' from God (1 Cor 4:5).
3. God's building (v16,17). God will destroy those who destroy His church. Do we value the Church (His Temple). The Corinthians were being individualistic rather than community. All is theirs in Christ, the leaders are their servants. Unfortunately, individualism is entrenched in our Western Christianity.