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 & 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?