"There are three stages, which should normally be followed in the reduction of social principles into practice. First, one reviews the concrete situation; secondly, one forms a judgment on it in the light of these same principles; thirdly, one decides what in the circumstances can and should be done to implement these principles. These are the three stages that are usually expressed in the three terms: look, judge, act" (Mother and Teacher, Pope John 23rd).
Christians are looking at themselves and God's word and wanting to change the world to correspond to this thinking, which is also the way we become more spiritual.
Narrowing the point of view, the social teaching is part of the magisterium of the Church's prophetic voice. The universal teaching office of the Church: "It is the expression of the way the Church understands society and of her position regarding social structures and changes" (Compendium #79).
This teaching comes from the scriptures and tradition, revealed to us by God in our consciences, intellects and the natural law. "This is not a marginal interest or activity, or one that is tacked on to the Church's mission, rather it is at the very heart of the Church's ministry of service" (Compendium # 67).
This is why Paul VI established the Committee for Justice and Peace in the Vatican. "This doctrine in turn is integrated into the Magisterium of the Bishops who, in the concrete and particular situations of the many different local circumstances, give precise definition to this teaching, translating it and putting it into practice" (Compendium #80).
Whether the Christian wants to follow the teaching or not is up to the individual conscience, but at least they should not speak out at the bishops for being 'followers of North Korea' and telling the priests 'they are involved in politics'. This is not the correct attitude of a Christian. At least, they should listen and have respect for the teaching, even if they are not able to follow it.
There are also many non-Catholics who have respect for this teaching and try to make it part of their vision of society. In the recent election in Korea, 77 Catholics were elected to the parliament, and the hope is they will be working for the common good of society.
Today is the Church's birthday: Happy Pentecost.