Quoted from the first encyclical of Pope Benedict, Deus Caritas Est.
The Church cannot and must not take upon herself the political battle to bring about the most just society possible. She cannot and must not replace the State. Yet at the same time she cannot and must not remain on the sidelines in the fight for justice. She has to play her part through rational argument and she has to reawaken the spiritual energy without which justice, which always demands sacrifice, cannot prevail and prosper. A just society must be the achievement of politics, not of the Church. Yet the promotion of justice through efforts to bring about openness of mind and will to the demands of the common good is something which concerns the Church deeply.
The Church, thru some of her constituents, sometimes meddle a bit too often with the workings of the governement, but I think it’s justified. A just a society ought to be a government’s main objective, not the Church’s.
Given our history where the boundary between Church and State has been crossed too many times, it should not a be a surprise when the Church takes an active role in our society. It is this innate desire for the Good that ought to move us – as officials in power or as ordinary citizens – to achieve (or at least, try to achieve) what is best for our society.