We all have excuses don't we? Excuses of why we don't want to do the dishes or excuses of why we made a mistake. One of the biggest excuses I see is this one, "why go overseas to reach people when we have so many people here that need to be reached?"
To start off, Jesus didn't believe this thought process. Jesus said this in His final words before heading home to Heaven:
"Jesus came and told his disciples, “I have been given all authority in heaven and on earth. 19 Therefore, go and make disciples of all the nations, baptizing them in the name of the Father and the Son and the Holy Spirit. 20 Teach these new disciples to obey all the commands I have given you. And be sure of this: I am with you always, even to the end of the age.” Matthew 28:18-20.
I'm sure you have read or heard of this passage before. I believe it is the foundation of the mission of the church. It is Jesus' marching order for the church in every generation.
Notice Jesus did not say, "Go and make disciples of Jerusalem" or "Go and make disciples of the country you live in" but went with a global mission rather than just one-dimensional.
The big excuse is to limit the mission of the local church to be one-dimensional.
Look at the layers of mission that the early church began with in Acts 1:8: "But you will receive power when the Holy Spirit comes upon you. And you will be my witnesses, telling people about me everywhere—in Jerusalem, throughout Judea, in Samaria, and to the ends of the earth.”
The kind of mission Jesus called churches to seek to become is making disciples of all nations.
First, Jesus commanded it. Second, it teaches us to not become comfortable reaching people we are comfortable reaching. Third, Jesus has a heart for all people to be saved, not just Americans. Fourth, the local church exists to reach everyone. Fifth, Heaven will be populated with every nation.
Finally, I believe one of the biggest ways to help develop mature disciples is to give them a worldview of the gospel.
Lead people to go on mission to experience it short-term so when they return they will live with a better understanding of how God is moving all over the world.
A God-sized mission that doesn't include missions outside of America doesn't live up to the mission that Jesus delivered moments before returning to Heaven.
Let's always ask God to help us reach people that are far from Him locally, nationally and internationally.
The question instead of "why" should change to "why not" in reaching beyond the shores of America to the world.