The Church is the family of God.
I believe this is a true, Biblical, and important statement. But I need to add some clarification.
When we say the Church is a family, most people picture a husband and wife with 2.3 kids. They imagine a tiny little group where everyone is close emotionally and knows everything about each other. They care deeply about one another and spend all their time together.
A local Church may start as a tiny family, but families expand. I have four boys, and one day I hope they each marry and have children. And they grow up to have their own kids. With time, my intimate little group will grow to a large gathering. In fact, once we get big enough, we will only get together on special occasions and at family reunions.
As a Church does the work of sharing the message of Jesus and discipling people, new people will be added. When that happens, the dynamics of the family change. No longer does Sunday morning feel like an evening at home with tight-knit relatives. Now it is more like a family reunion held to bring everyone together.
The goal has never been to keep the family small or for us to know everyone intimately. Growth is good. Just know that as it happens, things change.
One day I pray God will allow me to sit at a table surrounded by my children, their wives and children, grandchildren, and their wives and kids. At that moment I will be glad that we decided not to stay small.
The same is true for the Church.