As we know, the story goes that a Jewish man falls into the hands of robbers who beat him half to death while he's traveling between Jericho and Jerusalem and leave him for dead. The priest and Levite who come along and pass on the other side do so according to Jewish laws of cleanliness; they cannot touch anything dead for fear of becoming unclean. So Jesus here once again points out that cleanliness laws are not meant to be followed so strictly that we lose sight of the greatest commandment: to love God and, in turn, our neighbor.
Here's where it gets more interesting. A Samaritan comes and saves the man, bandaging the wounds and taking him to a nearby inn where he pays the innkeeper the necessary fees and promises to pay any extra expenses on his way back through. End of story right? The Samaritan does the good deed, huzzah!
Well, think of this: Remember that the Samaritans outright hated the Jews and Jews despised Samaritans just as equally. These were bitter enemies, yet one of them chose to save his enemy. Now for a Jewish person, they would rather die, yes, DIE before they took any aid from a Samaritan. Imagine the man's surprise later if he found out who saved him!
If we were to modernize this story and put it into our context, Jesus might be saying that it was an American who fell into the hands of robbers, and a member of al Qaeda (the Taliban) saved him. How crazy would that be? Imagine the media coverage and reaction from people. Yet, this is how radical Jesus' message was to the people of his time, and how radical it is to us today. Let's always remember who our neighbors are, despite the circumstances we know one another.