The Apostle Paul explains the doctrine of the church so that we might understand what God has done and so that we may understand who we are. And in calling us to understand who we are and what we’re called to do, Paul says that we’re the church. We’re the church that God ordained from the foundation of the world. We’re His people; we’re His household, so let the church be the church.
Paul gives great attention to ecclesiology, the doctrine of the church, in his letter to the Ephesians. In fact, we could say Ephesians answers this question: What is the church? In Ephesians 2:19–22, the chief metaphor Paul uses is that of a building—the household of God. Christians are part of the household in the sense that they have been adopted into the family of God, which is another image that Scripture uses to describe the church. But here the accent is not so much on the family of the household as it is on the house of the household: “[We] are fellow citizens with the saints and members of the household of God, built on the foundation of the apostles and prophets” (vv. 19–20a).
Paul says the foundation of this building called the church is made up of the prophets and the Apostles, that is, the Old Testament prophets and New Testament Apostles. Why? It’s because the prophets and Apostles are the agents of revelation by whom God speaks to His people. They delivered the Word of God. Another way of saying this is that the foundation of the church is the Word of God.
That’s why we must pay close attention to our doctrine of Scripture. The attacks launched against the integrity, authority, sufficiency, and trustworthiness of Scripture are attacks not upon a side alcove of this building. They don’t put a dent in the roof of the church. They’re attacks on the church’s very foundation.