1 Corinthians 3:6–7 (NKJV)
6 I planted, Apollos watered, but God gave the increase. 7 So then neither he who plants is anything, nor he who waters, but God who gives the increase.
There is a fallacy among Christendom today and it is: Our programs and our charisma are what will lead men and women to Christ. But Paul counters that by saying to the Corinthians, God gave the increase. The increase is not based on any ‘wow’ factor a church may perform.
The Corinthian church was fighting over who was the best leader. Their pride was causing contentions and divisions. Paul says, all we did was plant and water, without God there would be no growth.
And by the way, Paul is not talking about numeric growth. The context is spiritual growth, i.e, the spiritual man vs. the carnal man. Numeric growth means absolutely nothing. However many attend a church, the question is, are they spiritual?
How can a man, woman, boy or girl grow spiritually? It is from planting and watering first. How did Paul plant? He did it through consistent teaching of the word of God among them (Acts 18:11). How did Apollos water? First, he was teachable (Acts 18:26), then he reinforced everything the apostle Paul taught the Corinthians (Acts 18:28; 19:1).