The Covenant Community
A basic tool for interpreting the bible is the concept of the life setting of the passage (Sitz im Lieben). This principle basically says that the meaning of the passage can only be understood in the context in which it was developed. Thus the bible becomes an extended sermon to a congregation and church context with all the insider jokes and references to the hot topics of that congregation.
The concept of the Covenant Community is an application or related concept to that of the life setting of the passage. One way of looking at the bible is to trace the history of the people of God and their interaction with God. Close investigation will show that this interaction is based on a series of covenants that are kept to a greater or lesser extent by the people of God. Taking a further step brings us to the realization that we can define the boundary of the people of God based on these covenants. We can state that the people of God were the patriarchs based on the Abramic covenants. The Israelites in a similar manner were the people of God based on the Sinaiaic covenant (Land and the ten commandments). The Israelites were the people of God during the monarchy under the covenants that came before and the additional covenants around the temple and the Davidic throne. These covenants especially, later flowered in the New Covenant which defines the church universal as the people of God.
Along with defining relationship between God and his people and also describing how the people should live, to a greater or lesser extent the covenant also defines the things that are important to the life of the people under the covenant such as the government of the people of God. This may be explicit as in the case of the Sinaiaic covenant which had a complete system of law attached, or the Davidic covenant which defined who would rule. It may alternatively be implicit in that the style of government flowed not so much from stipulation but out of the activities in fulfilling the covenant. This is the case with the new covenant. The covenant speaks loudly about renewal of relationship and the sharing of the good news but doesn't stipulate how the church is to be governed in the kind of detail that we find in the Sinaiaic covenant. Apart from the statement about Peter being the rock on which the church will be built, descriptions and structures of church government and general ministry were identified and crafted by the church of the new covenant in an attempt to meet the requirements of that covenant. One of the reasons why the governance structures in the New Testament church appear to change between books is just this reason. Another reason is that each church - and books belong to different churches or communities - had a different governance structure at least at the micro level if not the macro level.
The concept of the covenant community as described is useful for interpreting the bible. I remember asking why the church should be involved in Social Action. I was directed to the many passages in the prophets that talk about reaching out to the poor etc. I was left unsatisfied. The covenant under which I operate doesn't have the strict stipulations that resulted in those passages, they belong largely to the Sinaiaic covenant. However, it would be perfectly valid to develop a basis for social action - anything from feeding the poor to advocacy to the government - from the love for others that is a key part of the new covenant.
Another example is the issue of giving to the church. In conservative circles there is a strong push to tithe. However the concept of a tithe comes from the old covenant and was almost a tax. Most of the biblical passages I have seen quoted to support the concept of tithing today are from the Old Testament. Under the New Covenant, the church's initial response to giving ranged from giving everything (Acts 4:34) to only giving on the basis of famine relief. As an aside, I personally tithe, and plan to continue to do so on the basis of supporting the extension of the kingdom of God.
Clearly an understanding of the concept of the covenant community speaks into how we can use the text to develop theology. In my two examples, the actions or conclusions that arise from the theology may have been right even though the theology was wrong. In other cases the actions or conclusions are also wrong. A good example of wrong actions and conclusions can possibly be found in the history of slavery, where a justification for owning slaves under the new covenant came from a passage from before any covenant.