Before I get into this… a bit of a confession time. I may not be the great exemplar of a missionary. I am not adept at language. I am an introvert, when it seems as if the extrovert is the ideal promoted. I am prone to be a bit grumpy. I am also not particularly evangelistic. Oh yeah, and I am horrible at fundraising. (Not all of these are that important. I think the jury is out still as to whether introverts or extroverts make better missionaries. And, in the age we live in, missionaries in most parts of the world are needed more in skills training and leader development rather than being evangelizers or churchplanters… the latter roles issionaries are usually second-rate as compared to locals.) It is still fair to say that these are all pretty good reasons for me NOT to be involved in missions. Confession time over.
You know… some people just really really should not go into missions. I know we have really rousing missions conferences with “altar calls” to get people to commit to mission work, but some really should be discouraged from this. I know many people think that God gives certain people a divine moment that tells them they must be missionaries— no turning back. Not so sure, and this matters, because there is dangers to the wrong people going into cross-cultural ministry. That is because although mission work can truly advance the Kingdom of God, done wrong it can also hinder or undo it.
The people who always make me the most nervous here in the Philippines are the highly ethnocentric missionaries. Usually, these are Americans who often embrace many of the “Ugly American” stereotypes that we were warned about back in my Navy Days before our ship sailed into foreign ports of call. It is interesting that the US Navy tried to drill this concern into our minds while many groups (especially churches sending individuals or short-term mission teams) do not. Some such mission folk are loud and abrasive, and think they know more than locals. Some seek to bring over their churches from the US bringing their own style, doctrines, and prejudices to be imparted into their mission churches. I know of two people who were kicked out of the Philippines because they were missionaries. The Philippines is so lax on enforcing rules regarding mission work that it is hard to imagine any being sent home for illegal mission work. However, the fact was that it was the local church they were working with here that turned them in to the BI (Bureau of Immigration). I never did find out what this American couple did that would motivate Filipinos to turn on them (a rare thing indeed). While I said this as if only an American thing, I have seen a few other nationalities (I will leave these unlisted) that feel the temptation to bring in their superior attitudes to the field. If you feel the need to bring your political perspectives and train up your people in them on the field, you are probably in the wrong job.
Some people struggle with being self-driven, and self-accountable. While everyone needs accountability in mission work, the oversight is commonly less than at home. In most cases it is easier to get away with laziness or acting out when one’s boss is hours away. If you need someone looking over your shoulder to make sure you are working, mission work is probably not for you.
Some people struggle with flexibility. Cross-cultural work involves cultural flexibility. Mission work, in general, requires activity flexibility. Rarely is one day like the next. If one needs routine, or can’t handle being expected to behave in ways that are markedly different than one was raised up, mission work is probably not the best for you.
If you are success-oriented, and want to be a big name… again probably not ideal to be a missionary. Even if you are fairly well-known to a small group of people where you serve, people in your home country are likely not to know you. The activities likely to get one to be well-known (like getting killed for illegal trespassing on lands of hostile locals, or getting caught sexually molesting MKs) are exactly the things one REALLY SHOULD AVOID. Frankly, most famous missionaries, like St. Paul or William Carey, really became famous mostly after their deaths.
If money given to you as a steward for ministry feels like your own money… you probably should not be a missionary.
A great list is 10 Reasons NOT to Become a Missionary, by Laura Parker.