As we have begun a sermon series Healthy Church, I thought it might be good to define what a church is, especially because the New Testament definition of church has been obscured in modern times by differing notions.
The South is often described as having a church on every corner. Drive any length of time around the Triad, and you will probably see that this is the case. Yet, this description of the church is foreign to how the New Testament defines church. Where we are often quick to have some kind of structural building pop into our minds when someone is talking about a church, the Bible has in mind an assembly of people. In fact, the Greek word found in the New Testament that we translate as church, ekklēsia, is defined as “congregation; assembly, gathering.” Understanding this will get us started in defining the church.
Mark Dever, pastor of Capital Hill Baptist Church and president of 9Marks, has a PhD from Cambridge in Church History. Understandably, he is considered to be a modern-day doctor of the church. His definition of church is as follows: “The church is the body of people called by God’s grace through faith in Christ to glorify him together by serving him in the world.” This is a great definition and worth going through in chunks.
The Body of People Called by God’s Grace through Faith in Christ
First of all, the church is not a building but a people; not just any people but a specific people. Paul tells the elders of the church in Ephesus that the church of God was purchased by Jesus’ blood (Acts 20:28; cf. Rev. 5:9). The church is purchased out of the slavery of sin and the punishment of death. The true church is made up of those who have taken hold of this salvation through faith: “For you are saved by grace through faith, and this is not from yourselves; it is God’s gift—not from works, so that no one can boast” (Eph. 2:8-9). If you believe that Jesus Christ was the Son of God sent to be an atoning sacrifice for your sins and was raised again on the third day, that faith is a gift from God’s grace, and you are a part of God’s church.
This brings up something that needs to be clarified. You may have heard people refer to the “universal church.” Theologians call this the “invisible church.” It is made up of all those who have been saved, are saved, or will be saved (of which only God knows), and this expression of the church is often discussed in scripture. But there is also the local or visible church. It consists of the saved-by-faith Christians that meet in a certain place together. A local church is a particular segment of the universal church. This is what is meant when Paul refers to “the church in Cenchreae” (Rom. 16:1) or John’s reference to “the seven churches in Asia” (Rev. 1:4).
Even further, a local church is not necessarily made up of everyone that shows up on a Sunday morning, but is made up of the truly saved believers that are a portion of those people. In the modern day, these people are usually marked off by membership. To become a member of a local church is to say that you have been saved by Christ and are committed to being a part of that local expression of the universal church.
To Glorify Him Together
Peter says that the people for God’s own possession (the church) were purchased “so that you may proclaim the praises of the one who called you out of darkness into his marvelous light” (1 Pet. 2:9). In this manner, the church’s mission is the Great Commission: “Go, therefore, and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit, teaching them to observe everything I have commanded you” (Matt. 28:19-20a). These two things—“proclaim the praises” and “make disciples”—are integrally linked as faith comes by hearing the proclamation of the gospel message (Rom. 10:17). When people confess Jesus Christ as Lord, God is glorified (Phil. 2:9-11).
The church is a group of people that long for God to be glorified in their neighborhoods and in their city and in the world. And the way to do this is to proclaim the good news of Jesus both with our words and with our lives.
By Serving Him in the World
The church does not hide out until Jesus’ return. Like we have seen, the church’s entire existence is for the glorification of God through the praises of the peoples of the world. Jesus prayed to the Father: “I am not praying that you take them out of the world but that you protect them from the evil one. They are not of the world, just as I am not of the world. Sanctify them by the truth; your word is truth. As you sent me into the world, I also have sent them into the world” (John 17:15-18).
Yet serving Jesus in the world does not just mean proclamation, it also means living according to the gospel proclaimed (Phil 1:27). It means loving the brothers and sisters in the church (John 13:35), which is impossible to do well without committing to a local church. It means serving in the community (Gal. 6:10). It means being the body of Christ in the world (1 Cor. 12:12-27).
We say at Mercy Hill that the Church is God’s plan A for the world, and that it is. To know the definition of the church is to know the importance of the church. Keep this in mind as we continue on in our Healthy Church series.
-Alex Nolette (Equip Associate)
 The Greek New Testament UBS 5
 A Theology for the Church 1 ed. p. 768