Missionary or Theologian?

You're answer should be, "yes." Consider this quote from John Piper, when discussing Andrew Fuller:

What shall we learn from this? We should learn the vital link between the doctrinal faithfulness of the church and the cause of world missions. The main impulse of our day is in the other direction. Everywhere you turn there is pressure to believe that missions depends on not disputing about doctrine. As soon as you engage another professing Christian in controversy over some biblical issue, the cry will go up: “Stop wasting your time and be about missions.” What we learn from Fuller is that those cries are at best historically naïve and at worst a smoke screen for the uninhibited spread of error.

One crucial lesson from Andrew Fuller’s life is that the exegetical and doctrinal defense of true justifying faith and true gospel preaching in the end did not hinder but advanced the greatest missionary movement in world history. Getting Christian experience biblically right and getting the gospel biblically right are essential for the power and perseverance and fruitfulness of world missions.