The Church has been understood as a universal community, at least by the apostle Paul. Perhaps a better terminology is the household of God, as Ken Schenck uses in Quadralateral Thoughts.
But, how is this universality understood today? Conservatives of course point to Scriptures, while the Progressives point to science. Conservatives believe that God made one humanity in Christ, while progressives believe that we are one humanity.
Conservatives do things for the glory of God, while progressive do things for the "common good", the betterment of mankind. Conservatives tend to understand their identity in specified and special terms. Progressives understand this tendency as group identification. Group identification distinctifies one group from another, as this was what has transpired throughout the course of history with any kind of group; religious, political, cultural, etc. Humans love to create an identity by maintaining their distinct boundary markers. But, progressives question whether some boundary markers are healthy to maintain.
The question of mental health and "the common good" is the question of one's reason for boundary markers. What is a healthy boundary marker? Both conservative and progressives would agree that a good boundary marker would be the personal convictions, or commitments of a person, or the laws that define a nation's culture. Laws define what is deviant. While deviancy is an important value to uphold in a civilized society, what defines unhealthy reasons for boundary maintainence?
When one describes an individual commitment or conviction, or a nation's laws, both conservative and progressives agree that these should be respected. But, religious identifiers or boundary markers are harder to rally full agreement. Religion defines itself upon the "rules of faith", but progressives question the "rules" as being "right" in describing faith, as faith is a personal commitment to value. Religion, on the other hand, has many ways of maintaining its group identity.
Religion bases its claims of identification of beliefs, a divine figure, a culture, group "rules". Religion delights in coformity and thinks of itself in conservative circles, as exclusivist. Relgion colors one's perception and perspective and breeds prejuidice, and the prejuidice is reinforced by sacred texts, or sacred persons. Progressives are more open to define religion in objectified terms.
With many distinctions between the conservative and progressive, there has been an attempt to unify both through "purpose" or "teleos". In Chrisiian circles, this attempt has been based on "the Kingdom of God" and the "common good". The public square meets the Church on the Church's "terminology' , while using the Church's gifts for "the common good" of humanity. There is nothing wrong with this unity of purpose, as long as all individuals that are affected are informed of the specific requirements upon their life. If a "purpose" is useful for the "common good" (pragmatism), especially if it is underwritten in the conservative's mind, by "God", then the State can bring about its plans in a peaceful and unified way.
True progressives, though, would question the wisdom of combining Church and State in this way, as it brings about an intrusion of government into private lives. Privacy is a value in American culture for it repects the individual. But, both conservative and progressive moralists bring "the rule of law" upon others in the "name of God" (reconstruction, restoration, or social gospel), to teach others about God's rule. I question how this is anything other than Shai ria Law, or Constiantine's Empire...
Although I am not clear as to how I view Church and State, I question the ways in which moralists understand themselves as a "superior" breed of humanity. Whether one rules as the Taliban, or "legislating the Pentateuch", both do not breed tolerance for difference, or an openness to intepretation of that law. Laws define a nation's values, and America was founded on freedom of religion and a separation of Church and State. This separation was not to be a "wall", as a Founding Father claimed, but was to maintain the boundary of public/private, so that individuals could come to their own convictions, values, and faith, which is found within the culture's social structures of family, church and comminity. Objectifying morals transgresses the universal ethic of "doing unto others", "the categorical imperative", even when the moralists is convinced of their "rightness" of conviction. The battle of morality should be for the conservative in love from a pure heart, while the progressive should use reason to explore morality's reasonableness in scienctific discovery and philosophical discussion.