1 Corinthians 3:6

I have planted, Apollos watered; but God gave the increase (KJV)

Then: A succinct summary turns the wisdom of the sophists to the work of farming. That's a lowly occupation about which non-farmers usually know everything. So Paul tells them he did the planting, i.e, brought the word of Christ to the Corinthians. Afterwards Apollos did the watering by helping them understand and use what they'd learned. But all the time the true overseer, God, made sure the fruit was unblemished, plentiful, and full in order for the process to be replicated over and over.

Now: The church consists of workers with specific jobs. God directs the workers. No single one of his workers can be elevated by members of the church to being in charge of the process. Only God has the power, knowledge, and presence (omnipotent, omniscient, and omnipresent) to do that. Verses 6 to 9 are always noted as an outstanding metaphor in Paul's teaching techniques. Morris (p.63), among others, explains that verse 3 verbs are in the past completed tense when referring to Paul and Apollos, but the one for God is in the past imperfect designating an ongoing process. That means today's Christians and those who follow us are still part of that plan, an ongoing process until the time of the second coming. We are all blessed by his love.

Extra source: The First epistle of Paul to the Corinthians: an introduction and commentary by Leon Morris (Grand Rapids MI: Wm B. Eerdman's, c1985, 2002) online at http://books.google.com/books?id=lNc0AYIqQvAC&dq=Corinthians+Morris&printsec=frontcover&source=bl&ots=NwNTeWfd4I&sig=XgqcdeZIJ7jIfOrxTT7PUqQqo_4&hl=en&ei=F-MkS82TPIvWlAfW55D-CQ&sa=X&oi=book_result&ct=result&resnum=2&ved=0CAwQ6AEwATgK#v=onepage&q=&f=false