Toward a Trinitarian Ecclesiology

by Matt Capps June 13, 2019

No doctrine is more fundamental to our theology than the doctrine of God. Concerning the nature of God, we must firmly proclaim that the God revealed in Scripture is the only true God (Deut. 6:4; Isa. 45:5). This truth concerning the nature of God is expressed further in the historic doctrine of the Trinity, which affirms that God is one in essence and three in person.

The triune principle at the heart of God’s nature is unit band distinction, that is, all three persons of the Trinity are equal in essence yet distinct in person. The distinction among Father, Son, and Holy Spirit can also be seen in the way they relate to one another and the role each plays in accomplishing the plan of redemption.

Within the New Testament, the unity of our Triune God is clearly portrayed in the baptism and prayers of Jesus (Matt. 3:13-17; Mark 1:9-11; Luke 3:21-23; John 17). The distinct function of members of the Trinity can also be demonstrated as to their roles in the mission. For example, Scripture states that the Father sent the Son into the world (John 3:16). Likewise, after the Son returned to the Father (John 16:10), the Father and the Son sent the Holy Spirit into the world (John 14:26; Acts 2:33).

The Trinity as a Framework for the Church 

British theologian Colin Gunton once argued that one shortfall of modern ecclesiology derives from the fact that it has rarely been rooted in the conception of the Triune God. This observation is worth consideration. I would argue that the unity of the Triune God, even as each member is distinct in his function to accomplish the plan of redemption provides a framework by which we can understand the unity and the mission of the church.

One might even argue that we cannot formulate a proper ecclesiology without reference to the doctrine of the Triune God. For the purpose of this article, I will utilize three of the primary New Testament metaphors for the church, namely, the people of God, the body of Jesus Christ, and the temple of the Holy Spirit, to build a framework for a Trinitarian ecclesiology. Perhaps a more comprehensive understanding of how the doctrine of the Trinity informs our ecclesiology might nourish a more holistic understanding in at least two particular areas, namely, the unity and mission of the church.

The People of God

The Apostle Peter affirms that the church is a people belonging to God (1 Pet. 2:9-10). That God the Father has called to himself a people establishes the foundational identity of the church as the family of God. In the New Testament, the language “children of God” is reserved for people who have been called by God and adopted through Jesus Christ by the regeneration of the Spirit. Therefore, the essential unity of the church as the people of God finds its source in the oneness of the Triune God, who exists in unity and diversity. Similarly, the church is called to picture unity in diversity without division.

The Apostle Paul makes clear in his letters to the New Testament churches, both Jew and Gentile are included in the people of God, unified through faith in Jesus Christ. The problems Paul addresses in the Galatian church regarding the divisions of Jews and Gentiles highlights the necessity for unity as the people of God in order to maintain the gospel, and thus faithfulness to the mission of God. In this sense, the metaphor of the church as the people of God not only speaks to our unity within diversity but also unity in our mission. The Son sends the church into the world with the power of the Spirit on mission to glorify God by making disciples of all nations, baptizing them in the Trinitarian name of “…the Father and of the Son and of the Holy Spirit” (Matt. 28:19). Thus, as the people of God, we are unified in Christ and sent in the power of the Spirit to proclaim the gospel in order that people from all nations might become part of God’s family. This mission is accomplished as the church functions as the body of Christ for the glory of God as witnesses in the world.

The Body of Christ

In Romans and 1 Corinthians, the metaphor for the church being the body of Christ places the emphasis on the relationship that members of the body have with one another – at the Lord’s table and in the Spirit’s baptism (1 Cor. 10:16-17, 12:13). The church is called to rise above the natural divisions of the world through the Spirit-empowered common life shared in Christ. Because of our unity in Christ, we belong to one another in our mutual love and concern for each another (Rom. 12:5; 1 Cor. 12:25-26). This unity is a powerful witness to the world, as Jesus demonstrates in John 13:35. Even more, the metaphor of the church as the body of Christ not only speaks to our unity as necessary for our mission, but also to our equipping for the mission.

Our unity in the mission as the body of Christ pictures the church as composed of individuals with diverse spiritual gifts (Rom. 12:4-5, 1 Cor. 12:14-20). God gives these Spirit empowered gifts to the body of Christ in order to carry out her ministry to the glory of God. The metaphor for the church being the body of Christ is especially important as one considers that no one member of the body has all the spiritual gifts necessary to fulfill the ministry of the church for her mission in the world. Jesus Christ is the only person who has ever walked the earth embodying all of the spiritual gifts. However, as the body of Christ, made up of different parts, each member uses his or her gifts in for the health of the whole church and for her mission in the world. And as the body of Christ, we represent the temple of the Spirit on a mission to expand the glory of God throughout the world.

The Temple of the Spirit 

Just as the physical temple of the Old Testament functioned as the dwelling place of God, and the gathering place for worship, the New Testament church, is composed of regenerate believers as “living stones” making a spiritual temple, or spiritual house (1 Pet. 2:5). Paul makes this more explicit in his letter to the Ephesian church, in a Trinitarian formulation that establishes Jesus Christ is the cornerstone of the church, “…in whom the whole structure, being joined together, grows into a holy temple in the Lord. In him you also are being built together into a dwelling place for God by the Spirit.” Paul also envisions the church as the God’s temple with the foundation of Jesus Christ, in which the Spirit of God inhabits or indwells its members (1 Cor. 3:9-17; 2 Cor. 6:16-18).

Therefore, the church consists of a unified people, worshiping God through the Son, in the power of the Spirit. Our missional task as the temple of the Spirit is to call forth worshipers by proclaiming the gospel in the whole world as a testimony to all nations, until the fulfillment of the mission culminates in the new heavens and new earth, when people from every tribe, tongue, and nation will worship around the throne as one (Rev. 7:9).


In the doctrine of the Trinity, the church is given a pattern for unity and participation in mission. As proposed in this article, each metaphor relates the church to a distinct member of the Triune God. However, within each metaphor, we witness the unity of the Triune God in mission. After all, the church is called to God in Christ by the Spirit, and the church provides a picture on earth, although it is a broken picture, of the communion in person and plan of the Triune God. Just as God the Father, God the Son, and God the Spirit are deeply unified with one another and unified in mission, so too is the church called to a unified life on mission as the people of God, the body of Christ, and the temple of the Holy Spirit.

Editor's Note: This post originally appeared at the blog for Credo Magazine and is used with permissions.