In the Christian world, you will hear of members say phrases like, "going on missions" or "supporting missions." They are most likely be referring to the word meaning a group of people going to a foreign country to preach the Gospel and/or assist with relief.
Why does the definition have to include the word "foreign"?
I mean, Jesus said, "Go into all the world and preach the gospel to all creation." In another Gospel, He says it this way, "Therefore go and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit."
There is no place in there that I see him implying that you have to travel by plane to get there.
In fact, your mission could be in the same room with you. Right now.
There is nothing wrong with traveling somewhere to minister to God's children. Nothing wrong. The problem arises when we come home and feel like we're no longer "on missions."
Our mission field is wherever we are. Whether a first world or a third world country, whether your home or away, our mission stays the same: to make disciples. To preach the gospel. To everyone.
I can guarantee you that there just as many lost souls that need Jesus' love in Africa as there are here in America. While you may not need to provide clean water for these people to drink, they have their own needs.
There is a certain leap of faith that you take to leave your hometown to go out and preach the Gospel to strangers of a foreign culture. I get that. But it doesn't discount the need, the necessity, for us to take another leap of faith, daily, to reach out to the people who aren't so strange and in fact know us to share the Gospel with them as well.