Ecclesiology, the theology of the church, is relatively young as a distinct theological discipline, and there is no one standard method of constructing an ecclesiology. As in other disciplines, there are a couple of basic approaches one can take, which can be described as “from above” and “from below.” Although all the relevant sources should ultimately be engaged with, it’s often useful to make this schematic distinction describing one’s starting point or emphasis with respect to the sources of theology.
From Above
The Wesleyan Quadrilateral — scripture, tradition, reason, and experience — is often used to describe the basic sources for theology. The first two are often described as “from above”, because they consist of special revelation as contained within scripture and the traditions of the church. From scripture, one might begin with the presentation of the early church in the Acts of the Apostles and Paul’s letters, or with the scriptural images such as the People of God, the Body of Christ, the Community of the Holy Spirit. From tradition, one might begin with the four creedal marks of the church: one, holy, catholic, apostolic.
Catholics might begin with Lumen Gentium, the Vatican II document on the church: which itself is grounded in scripture and tradition, especially the conciliar documents of Trent and Vatican I. Reformed Protestants might begin with Calvin’s Institutes on the Church. Ecumenically-minded Christians might begin with some of the WCC documents on Faith and Order, especially the influential 1982 document on Baptism, Eucharist, and Ministry (BEM).
Sacramental ecclesiologies, such as a eucharistic ecclesiology, may also be considered “from above,” as the sacraments and the liturgy arguably belong to the tradition of the church. These ecclesiologies adopt the liturgy, theology, and symbol of the sacrament to structure and explore the nature of the church.
In all these cases, the starting point is God’s special revelation to God’s people, as attested either by scripture or by the well-received tradition of the church. Ecclesiologies from above may tend to emphasize the mystery of the church over against the lived experience of the church in the world; they may also tend towards triumphalism.
From Below
Reason and experience are considered theological sources “from below,” because they are grounded in the human rather than the divine. Ecclesiology from below might start with the lived experience of the church, as Miroslav Volf does in After Our Likeness: who shows up at church? What do they do? And how do they interpret the meaning of what they do? Or, one might begin with the church as a human institution, applying the insights of cultural anthropology to observations about the structure and behavior of the church and its members. One might take a historical approach, beginning with the earliest documents we have from the apostolic and subapostolic eras, and considering how the infant church evolved in the presence of challenges from within and from without, throughout its history. One might examine the church from the perspectives of various groups that are arguably marginalized within the church: laity, women, people of color, people who have been colonized, people who are non-heterosexual, people with disabilities, people who are poor or oppressed for any reason by society at large if that position of lesser privilege is reproduced or even reinforced within the church.
In all these cases, the starting point is the church as perceived and experienced by its members. Ecclesiologies from below may tend to emphasize the historical reality of the church in the world over against its eschatological and sacramental aspects.
From the side?
Still another approach might be to treat ecclesiology as derivitive of one or more other theological disciplines. One might view some sacramental ecclesiologies in this way, as deriving ecclesiology from sacramental theology. Everett Ferguson’s work The Church of Christ, while clearly biblically grounded, derives ecclesiology from Christology and soteriology: his selections and interpretations of biblical texts are conditioned by his theological understanding of Christ and of salvation.
I suggest that ecclesiology can, and perhaps even should, be derived from theological anthropology and soteriology, because “people” and “salvation” are both required for an adequate description of the church. The church is the people who have been saved, or the people who are working out their salvation in fear and trembling, or the locus of salvation for all people. Logically, therefore, the nature of human beings, and the nature of salvation, must be combined to describe the nature of the church. Further, theological anthropology and soteriology provide a good balance of the human (from below, general revelation) and the divine (from above, special revelation).
And more specifically, one could derive a mimetic ecclesiology by starting from mimetic anthropology and the mimetic theory of the atonement. This is a topic I am presently considering for my master’s thesis.