Is Christianity just a belief system, or is it also a system for organizing and governing society? Works like "Mere Christianity" try and address common Christian beliefs and help recognize the diversity of belief systems within Christian sects.  The question is whether this is what all of Christianity is, or is there more?  Do Christian religious texts provide guidance on how to organize society and govern it with justice and fairness?

Added after reviewing comments through morning of 1/13/12:


Is it true that the family &amp; social laws in the Old Testament texts are to be ignored?  Yes/No? (provide supporting information)
If OT laws are to be ignored by Christians, does God/Jesus provide substitute laws in the New Testament texts?  I.e., if God thought it important to provide laws (in addition to requiring certain beliefs) to guide people prior to the New Testament, why has He not deemed it important to either re-affirm these same laws in the New Testament, or provide substitute laws?
Christianity is not, &quot;just a belief system&quot;, nor is it &quot;also a system for organizing and governing society&quot;.
It is simply the way for imperfect people to get into an eternal relationship with a perfect God, not by our good works but by the gift of Jesus. John puts it better than I can:

John 3:16
For God so loved the world that he gave his one and only Son, that whoever believes in him shall not perish but have eternal life.

Of course, there are consequences of this that affect the individual (e.g. a commitment to honesty and love) which then in turn affect society. (We are also instructed about our duty to society, e.g. &quot;pay your taxes&quot;.) But that's a by-product, rather than the central aim.
More directly answering your question, the Bible does not explain how to organise society but it does contain some very light weight (by which I mean, not overly proscriptive) examples of how to organise a church (e.g. mentioning elders).