The Book of Acts is invaluable for church life. What we see, among other things, is believers with a zeal to share the gospel with the lost wherever they are. Some people traveled far and wide (Paul), while others remained close to home. The common thread was a desire to see the good news spread to locations where it has not yet been heard.
Jesus Christ made his expectations clear enough. He told his followers that they would be his witnesses to the ends of the earth. He expected them to make disciples of all nations. This is not optional.
While the specific methods we use for reaching the lost may vary widely, the key is the end result. That result must be local bodies that work together to get the message to even the difficult to reach places. Christ's expectation that we do this is unavoidable.