I find it amusing when people say that to be a missionary one must go to different lands or cross cultural borders. I whole heartedly disagree with that. I will explain why in a bit first I want you to look at three passages.
Mat 28:19 "Go therefore and make disciples of all the nations, baptizing them in the name of the Father and the Son and the Holy Spirit,
Mat 28:20 teaching them to observe all that I commanded you; and lo, I am with you always, even to the end of the age."
Mar 16:15 And He said to them, "Go into all the world and preach the gospel to all creation.
Act 1:8 but you will receive power when the Holy Spirit has come upon you; and you shall be My witnesses both in Jerusalem, and in all Judea and Samaria, and even to the remotest part of the earth."
The word missionary is never found in the NASB, NKJV, ESV, or NIV. So where did it comes from. Our Lord Jesus entrusted us with a mission or a charge to preach the gospel. That is how we now get the word missionary which literally means one who carries out a mission. If one is a missionary of Jesus Christ, then he must carry out the mission of preaching the gospel. I would say that anyone, who preaches the gospel of Jesus Christ whether in the US or any other country is a missionary.
Looking back up that these verses we have to assume that not all of these things happen all at once. First we go. Go doesn’t necessarily mean to go a different country, or different State or even a different city. To be a missionary you don’t have to cross cultural boundaries or go to distant lands. It just means to go out wherever you are to preach the gospel. To go where the Lord as put you at that time of your life. If you think about it someone had to stay in Jerusalem and share the gospel with the Jews. We see that there was a Church in Jerusalem. How did that start unless someone was preaching the gospel there?
Go where? Into all the world, Jerusalem, Judea, Samaria and to the remotest parts of the earth. Many people think that go means to go to Africa or to South America or to anywhere but the US. The fact of the matter is that although many people in the US say they are Christians they have no idea what the gospel is. The US is in need of missionaries as much as many other countries. All of you that preach the gospel here in the US are missionaries as well as those that preach it in other countries. We must GO. We must preach the gospel to the world. Those that come to Christ are baptized and taught to observe everything our Lord commanded. Why should or would the Lord send you to a different country to preach the gospel, if you are not preaching the gospel where you are at now. Everyone that preaches the gospel is a missionary. No matter where you are in this world, that is where the Lord has put you and you need to go and preach the gospel. Those people need to hear the gospel to. So as fellow missionaries let us all go out and preach the gospel in the towns, cities, and countries where the Lord has put us for the time being. Let us be missionaries where we are at and if the Lord works out opportunities to go other places them let us go to other places.