In Acts 1, Jesus tells the disciples that they will be his "witnesses in Jerusalem, Judea, Samaria, and to the ends of the earth." This is a restatement of The Great Commission (Mat 28: 19-20), and refers to evangelism and missions. The mandate is usually divided into two types -- home and foreign. "Jerusalem and Judea" pertain to one's own city and country, while "Samaria and the ends of the earth" are considered missionary territory.
This understanding of the Great Commission effectively lets 95% of Christians off the hook for foreign evangelism. Mission work is reserved for a full-time minister who has received a personal "call" to leave his country and go work abroad.
In reality, it is not necessary to cross time-zones in order for the ordinary Christian to participate in the Great Commission. One can re-interpret the geographical references as degrees of cultural differentiation: Jerusalem is one's immediate family and neighborhood, Judea is one's own cultural niche -- a common ethnicity and language, Samaria is people of a different race OR language, and "the ends of the earth" are people of another race AND language. And all these types can be found in any large city.
I remember when I received my own "Samaritan call." It was when I became a prison volunteer at a jail two miles from my house. We had lived in that house for about 5 years without me even knowing that a prison existed nearby. When God opened the door for me to go there and attend services on a weekly basis, I was reluctant to go through that door -- "those people aren't like me." This was true but irrelevant. God put me there to learn from them before He wanted me to witness to them. I had to cross barriers of race, culture and class to meet with the inmates. The only things we had in common were gender and language.
This was a life-transforming experience, not for many of the inmates, but for me. It broadened my understanding of the Gospel's impact on people who were poor, less-educated, jobless and in trouble with the law. The Christianity I was familiar with needed considerable reworking to have any credibility with these men. We usually think of evangelism as something that impacts the world "out there," but it can transform the speaker as well. Whenever we take the message to Samaria and beyond, we will find that God works in us to deepen our understanding and experience of His revelation.
Imagine - participating in the work of the Great Commission without even having to get a passport!
For another post on a related subject see the paragraph on Bridge-builders in "All God's Children".