Matthew 5, 13-16 + CSDC and CV 

(CV 5b) This dynamic of charity received and given is what gives rise to the Church's social teaching, which is caritas in veritate in re sociali: the proclamation of the truth of Christ's love in society. This doctrine is a service to charity, but its locus is truth. Truth preserves and expresses charity's power to liberate in the ever-changing events of history. It is at the same time the truth of faith and of reason, both in the distinction and also in the convergence of those two cognitive fields.

This document is part of the Bishops' “munus docendi” (to teach)

CSDC 11a. This document is intended first of all for Bishops, who will determine the most suitable methods for making it known and for interpreting it correctly. It is in fact part of the Bishops' “munus docendi” to teach that “worldly things and human institutions are ordered, according to the plan of God the Creator, towards people's salvation, and that they can therefore make no small contribution to the building up of the Body of Christ”[10].

Notes: [10] Second Vatican Ecumenical Council, Decree Christus Dominus, 12: AAS 58 (1966), 678.

(Mt 5, 13-16) Men and women primary and fundamental way for the Church

[13] "You are the salt of the earth. But if salt loses its taste, with what can it be seasoned? It is no longer good for anything but to be thrown out and trampled underfoot. [14] You are the light of the world. A city set on a mountain cannot be hidden. [15] Nor do they light a lamp and then put it under a bushel basket; it is set on a lampstand, where it gives light to all in the house. [16] Just so, your light must shine before others, that they may see your good deeds and glorify your heavenly Father.

CSDC 62. With her social teaching the Church seeks to proclaim the Gospel and make it present in the complex network of social relations. It is not simply a matter of reaching out to man in society — man as the recipient of the proclamation of the Gospel — but of enriching and permeating society itself with the Gospel[78]. For the Church, therefore, tending to the needs of man means that she also involves society in her missionary and salvific work. The way people live together in society often determines the quality of life and therefore the conditions in which every man and woman understand themselves and make decisions concerning themselves and their vocation. For this reason, the Church is not indifferent to what is decided, brought about or experienced in society; she is attentive to the moral quality — that is, the authentically human and humanizing aspects — of social life. Society — and with it, politics, the economy, labour, law, culture — is not simply a secular and worldly reality, and therefore outside or foreign to the message and economy of salvation. Society in fact, with all that is accomplished within it, concerns man. Society is made up of men and women, who are “the primary and fundamental way for the Church”[79].

Notes:  [78] Cf. Second Vatican Ecumenical Council, Pastoral Constitution Gaudium et Spes, 40: AAS 58 (1966), 1057-1059. [79] John Paul II, Encyclical Letter Redemptor Hominis, 14: AAS 71 (1979), 284. 

 
[Initials and Abbreviations.- CSDC: Pontifical Council for Justice And Peace, Compendium of the Social Doctrine of the Church; -  SDC: Social Doctrine of the Church; - CV: Benedict XVI, Caritas in Veritate (Charity in truth)]