I thought I would post a good quote I found in Chapter 4 of the book, Good and Bad Ways to Think about Religion and Politics by Dr. Robert D. Benne. Chapter 4 of Benne's book is "Critical Engagement: Moving From Core to Public Policy."
From page 53...
As St. Paul says in Romans 13, government has been instituted by God to support good conduct while punishing the bad. The governor is the "servant for your good" (13:4). Christians not only must pay taxes; they can also participate vigorously in government. They can rightly expect and press government to give protection to its citizens from internal and external threats, to work for international order and justice commensurate with the power that it possesses, to encourage and monitor wisely a vibrant economy, to forge reasonable policies to conserve our habitat, to pursue justice for all (which includes safeguarding freedoms as well as providing an adequate safety net for those unable to care for themselves), and to exhibit and support humane values.