Sentence:  An action once universally condemned by all Christian churches and forbidden by the civil law is now not only approved by the overwhelming majority of Protestant denominations , but also deemed , at certain times , to be a positive religious <WSD>duty</WSD> . 
Meaning of the word marked with <WSD> tags:  the social force that binds you to the courses of action demanded by that force; every opportunity, an obligation; every possession, a duty"- John D.Rockefeller Jr