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 the Church; in every human person, a son or daughter of the One who wants to be called "our Father." In this way our relationships with our neighbors are recognized as personal in character. The neighbor is not a "unit" in the human collective; he is "someone" who by his known origins deserves particular attention and respect.
Source: Catechism of the Catholic Church (Vatican.va)