1 Corinthians 3:8 (NKJV)
8 Now he who plants and he who waters are one, and each one will receive his own reward according to his own labor.
We mentioned (1 Corinthians 3:6,7) that growth is not about numerical additions to the church. Paul says, he who plants…and waters are one. There is no counting sheep when the local church is unified–the local church is the Body of Christ, and it is one (as in a marriage, the two become one flesh).
When God looks at a church He does not count heads and neither should we. There is only one head, and it is Christ.
But the church, the body of Christ, is made up of individual waterers and planters. Each of them will receive his own reward. What the reward is Paul does not say (at least at this point). Whatever the reward is, or when the reward comes, everyone within the church will receive it based on his or her own labor. It is not like one of those group projects at school where one person does the excellent work and four other slackers get the same grade.