Not only do I agree with you that those serving as you describe will in all likelihood be included in the rapture and not miss it, ("Blessed is he that when the master comes finds them so doing,") but I also think a lot of people who are not even looking for it will be included in a way that Jesus described in His parable. But also there are many who were originally invited that do not want to come when the time is come and this angers God so He goes looking for those who were not even invited initially.

 

If I may summarize it in my own words, I think what happens is the time finally comes when the rapture is to take place and God gives the signal for Jesus to bring in the guests to the banquet but as He goes forth to do that and is calling the guests to come in, many begin to make excuse saying that now is not a good time for them. This represents the ones who originally were invited and said they would love to come, as long as it was "someday that no one knows the day or hour, but not today..." It's like that hideous song by Kenny Chesney that says "Everyone wants to go to heaven but no one wants to go now..." I'm like, speak for yourself, singing star loser...

 

But sadly, this song does describe many Christians who love the thought of being raptured or going to heaven just not now. So when Jesus does begin calling us to join Him, those who are not ready will begin resisting due to the reasons that Jesus described, such as having bought land, a yoke of oxen or just gotten married etc. I have heard over the years Christians in these kinds of situations come right out and say that they hope the rapture is not yet because they like their situation here now etc. This attitude towards the rapture as though heaven is second best to this current world, (barf) naturally angers God who spared no expense in preparing this banquet for us and graciously invited us in. Then He repeals His invitation to those who were not worthy and turns to those who were not originally invited and compels them to come in instead.

 

I know that mine is not a popular interpretation but I believe that according to the way Jesus told it that this change of heart in God and His decision to invite in the strangers happens only after the rapture has been turned down by those Christians who were originally invited and at the time that they turn it down, which is at the rapture time, not before. Then the invitation goes out to a non Christian world, and includes the forsaken of this world, like the homeless and probably a lot of the 3rd world countries like you described that missionary is serving in, where they have little to nothing and would love an invitation to God's banquet. When this first wave of new invites is done and yet there is room, this suggests that God has prepared a huge banquet and He wants it to be filled but those who originally were invited who turned it down were not worthy due to their inability to place proper value on God's invitation. This suggests that a lot of people who should have come won't, by their own choice. I don't even think this has to do with "sins" as we generally think of sin but rather is more like what occurred between Jacob and Esau. Jacob understood and desired the birthright though it was not his to claim, God gave it to him anyway. Esau, on the other hand did own the birthright and could have inherited it all but he did not appreciate the true value of it and he sold it for a meal. This made him profane and he was rejected. This is the test of worthiness.

 

Just as in the wilderness when the Children of Israel claimed that God didn't care about their children and brought them out here to die, etc. likewise many have accused God of not caring for the poor and hungry of this world. So, what if God does the same thing now as He did in the wilderness? What if God lets the ones who should have come in remain but takes in the ones that He was accused of not caring about? What if God sends His angels out at the time of the rapture through the whole earth and invites in the outcasts of this world wherever He finds them and quickly explains the gospel to them and invites them to come in and be cleaned up and have a banquet for free? I think His house will be filled with these people who will gladly accept this marvelous gift and those who have been too ignorant of the value of the offer will remain outside after the door is shut and then when it is too late, they will realize what they have done.

 

In order for this to be true, the rapture will have to take some time to be fulfilled and not be over in an instant but it may take up to a day to be complete. This would also give the wise and foolish virgins time to have their dialog as well. The Israelites were given a whole day from the time the invitation to enter and possess the Promised Land was given to the time when that invitation was closed and removed because they would not go in. During this time all who wish to enter in, I believe will be able to assuming they have on the wedding robe that one guy lacked and then he was cast out.

 

As Paul said every man's works will be tried for the day shall declare it of what sort it was... Which day, unless the rapture day? It sounds to me like we don't all get raptured and then while up in heaven have the judgment to see what our works were as many are now teaching, but rather the works are tried while it is still the day, and part of the prize is the rapture and part of the "outer darkness" is to miss it. Then Paul says of the one whose works burn up in that day, he himself shall still be saved yet so as by fire, which sounds like the tribulation to me. I think there will be more saved during the tribulation than in the church age, for the tribulation saints are a great multitude that no man could number but the church are a few saved out of the world.