Just as in the last chapter Paul talked about how Christians are not purely spiritual creatures who need not worry about what's going on around them, in this chapter he reminds them that being followers of Christ does not free them from being law-abiding citizens. Of course, several of the commandments are also no-brainers on both sides (no Christian would kill someone and think it was okay by Jesus), but generally, Christians should be members of their community at large so that the community of Christ may be among their neighbors.