15 This principle is the starting-point for understanding the great parables of Jesus. The rich man (cf. Lk 16:19-31) begs from his place of torment that his brothers be informed about what happens to those who simply ignore the poor man in need. Jesus takes up this cry for help as a warning to help us return to the right path. The parable of the Good Samaritan (cf. Lk 10:25-37) offers two particularly important clarifications. Until that time, the concept of “neighbour” was understood as referring essentially to one's countrymen and to foreigners who had settled in the land of Israel; in other words, to the closely-knit community of a single country or people. This limit is now abolished. Anyone who needs me, and whom I can help, is my neighbour. The concept of “neighbour” is now universalized, yet it remains concrete. Despite being extended to all mankind, it is not reduced to a generic, abstract and undemanding expression of love, but calls for my own practical commitment here and now. The Church has the duty to interpret ever anew this relationship between near and far with regard to the actual daily life of her members. Lastly, we should especially mention the great parable of the Last Judgement (cf. Mt 25:31-46), in which love becomes the criterion for the definitive decision about a human life's worth or lack thereof. Jesus identifies himself with those in need, with the hungry, the thirsty, the stranger, the naked, the sick and those in prison. “As you did it to one of the least of these my brethren, you did it to me” ( Mt 25:40). Love of God and love of neighbour have become one: in the least of the brethren we find Jesus himself, and in Jesus we find God.
Source: Deus Caritas Est (Vatican.va)