As you know, the Great Commission reads ‘Go therefore and make disciples of all nations, baptizing them in the name of the Father and the Son and the Holy Spirit, teaching them to observe all that I have commanded you.’
And you know that very many people teach that the ‘go’ should be taken as an imperative even though it is a participle. Too often this has been used to beat people over the heads about ‘going’ and becoming foreign missionaries (ever notice those so urging haven’t gone themselves?). Now, I have absolutely no problem with someone who sees God calling them to foreign missions but bad grammar should not be used to present bad theology. If the ‘go’ is to be taken as an imperative then only those who ‘go’ are the ones who are to make disciples—the rest of Christendom is left out of the Great Commission.
What follows is based on good grammar—discourse grammar specifically (check with Bob Bergen).
In discourse grammar the participles form the ‘background’ of situations—they are ‘offline.’ This is true of Hebrew, and it is true of Greek, especially the highly Hebraized Greek of the LXX and NT. That being true then the ‘going’ is back grounded. It is much better translated as such and not as an imperative. It should be, ‘wherever you find yourself placed by God, make disciples.’ Or ‘wherever you are going, make disciples.’
The grammatical structure of the text has all Christians, wherever they find that God has placed them, making disciples, not those who are specially called to ‘go.’ In my thinking, two of what could be argued are the most effective fields are nursing and teaching. I have taught junior high and high school in addition to the lofty teaching of seminary and I am married to a teacher and the father of a teacher. Teachers are the ones who encounter kids who are in the throes of growing up and learning to encounter the world. They desperately need a teacher who is a Christian and who presents a Christ like example to them.
So too nurses. Nurses, especially those in hospitals or hospice care, are encountering people in the most desperate of situations (I have been there with our sons, Michael and Nathan) and who most seriously need to be encountering on a regular basis a person who knows the LORD and who has a lifestyle and words to convey hope to those who most desperately need it.