"Every heart without Christ is a mission field. Every heart with Christ is a missionary." -- Vijay Menon.
As you know, I've been privileged to visit believers in many nations, including China, Ethiopia, Korea, and Ukraine. I went to serve them, but not as a missionary to non-missionaries. Rather, I viewed the believers in those countries as equal mission partners beside whom I had the honor of ministering.
The book of Philippians suggests that it may be a mistake to continue to refer to only certain people as "missionaries," because we are all to be on mission for Christ as we hold forth the life-giving word (Phil. 2:16). I love it how some churches refer to their missionaries as "mission partners" and their mission pastor as "pastor of missional living," for the responsibility of making disciples among the nations belongs to all of us.
It's simply a part of becoming Christlike.
Thanks for reading!