Paul writes in Ephesians that the church grows and builds itself up in love, as each part does its work. The church can seem to thrive when it is based on the charisma and gifting of one man, but underneath the facade of success will be fear, insecurity, and immaturity in the lives of the church members.
We do not grow by listening to fine sermons; we grow by putting into practice what we have learned; all food and no exercise make for a very sluggish athlete.
Instead, speaking the truth in love, we will in all things grow up into him who is the head, that is, Christ. To be like Christ, we need more than knowledge; we need to experience him working through us, and this takes time and practice and opportunity.
Leaders that deny others the chance to minister using their gifts do others and themselves a great disservice.
Finally, from a more pragmatic perspective, churches grow when church members like their church a lot, for when they do, they are motivated to invite others; they are motivated to get involved using their gifts and talents, and they are motivated to cultivate their relationship with God and others, which ultimately produces church growth – spiritual, emotional, and physical growth.
Healthy bodies grow; it is an immutable law.