Various Proposed Purposes
First Admin's view ...
The need for believers to serve one another is introduced through the idea of service to God. The previous service or worship to God consisted of the priesthood laws and operations.
In light of the idea of serving God as a "living sacrifice," the act of serving one's brother should be a trivial request.
The idea of service to one another occurs as the first step of a series, from chapters 12 to 15, by which Paul seeks to change the Roman attitude from selfish boasting into altruistic care for one another.
Other Views By Links ...
Note that views may be added directly by adding the same styled heading with the well-known author name or with the wiki user name.