[Social issues would not have to be "legislated" if people read and followed God's word]
Two problems with that.
1) There is no rational basis to elevate one person's idea of "God" over another's in regards to regulating civil/criminal conduct.  Our founding fathers even figured that out and the framers incorporated that into the Constitution with the separation of church and state.
2) Even if we could agree on one denomination (Christianity versus Judaism for example) we cannot even agree on what is "God's word" and how it should be followed.  Mormon's, Lutherans, Methodists, Protestants, etc. etc. etc. agree on the big picture but not so much on what usual falls under the concept of "social issues."