The term "good Samaritan" emerged in a biblical parable in the new testament, in which Jesus Christ directs his followers to love their neighbors as they loved themselves.
Currently, the expression was generalized and "good Samaritan" came to designate anyone who cares about others, who always acts in favor of the good, who seeks to help in any circumstance, without false interests.
Samaritan is the natural person of the region of Samaria, near Jerusalem. In Jesus' time, many Jews hated the Samaritans because they were considered unclean foreigners.
In the parable told by Jesus, reported in the Gospel of St. Luke, chapter 10, a doctor of the law asks Jesus what he should do to inherit eternal life. Jesus responds that it was necessary to love God and love one another.
When questioning who the "neighbor" was, Jesus responds by giving the example of the behavior of three men who passed by another who had been beaten. Two men (in the ranks of priests) passed the victim without providing help, but the third, a Samaritan, took care of him, took him to a proper place to be helped, and paid all the expenses. This benevolent man became known as the "Good Samaritan."
The conclusion reached by the doctor of the law was that the "neighbor" was the one who had mercy on the needy man, even though he was a stranger