The separation of church and state–that slippery topic–was dealt with recently with simplicity by the Holy Father. In speaking to the US Ambassador to the Vatican regarding ethics in politics, he said:
“The disturbing spread of social disorder, war, injustice and violence in our world can ultimately be countered only by renewed appreciation and respect for the universal moral law whose principles derive from the Creator himself.”
For the state to counter social ills, it must understand that societal problems are not primarily policy-oriented problems, simply a matter of the wrong combination of legislative forces. The problem is a problem in the human heart, a disconnect between the sinful creation and the holy Creator, that can be treated (if not cured) by acting in accordance to the Creator’s moral law.