So I'm probably wrong here, in every way. But I have viewed Matthew 22:15-22 (render unto Caeser...) as a fairly clear statement that Jesus wants us to live an orderly life in whatever society we live in but recognize that our salvation comes from our devotion to Him. We don't seek salvation based on our devotion to Caesar. Matthew 22:15 is one reason why I do not understand Catholics who believe (like you pointed out) that the government should be the agent of helping the poor and in effect our souls.
Thank you for your enlightening/educational response. You are correct that Bishop Foy does not speak for the entire church and that my post overgeneralizes. However, he probably represents a significant portion of Catholics and their thinking.