Catechism of the Catholic Church §2212 — excerpt
The fourth commandment illuminates other relationships in society. In our brothers and sisters we see the children of our parents; in our cousins, the descendants of our ancestors; in our fellow citizens, the children of our country; in the baptized, the children of our mother…
This translation is under copyright, so only the cited words are quoted here. Follow the link for the full text. Translation: English translation of the Catechism of the Catholic Church, 2nd ed. (Libreria Editrice Vaticana), as posted at vatican.va.