Often men who are missionaries are very driven, very focused, and very diligent. They thrive on overcoming obstacles and accomplishing things. The idea of “abandoning the work” that they have “poured their heart and soul into” can seem horrible. Why would they want to take a step back and go home?
But often, the missionary’s wife and children, though they love the work and the field, need some time to reconnect with family. A woman is usually much more relationship-oriented than men, so seeing her parents and family is very important to her. If she has sacrificed by leaving them for several years to go to the field, it is not wrong for her to want to see them every couple years. (And men, it would do you good to visit your family as well.)
Children also need to grow up to learn that though they should put Christ first that family is important and to be valued. They need to be able to spend some time with grandparents, to get to know their cousins, and to profit from the investment of other family members in their lives.
Often, depending on the country the missionary is working in, the missionary’s family may need some kind of dental work or medical treatment. Things like life insurance, a will, retirement, and other details like this are important and should not be foolishly overlooked with the excuse that they are unnecessary because you are a missionary. You may be a missionary but you still have obligation to take care of your wife and children. If you don’t provide for them, you are worse than an infidel. On a practical level, if you lose them, you lose the ministry because you become unqualified.
On a personal note, I think that our furlough has been very good for my wife and children. Teri has loved spending time with her sisters, her parents, and her friends here in America. Our children have really enjoyed and benefited as well. They loved living on the field and found it very difficult to leave, but this time has refreshed them to want to return to the field ready to do even more for God. I don’t want my family just enduring the mission field. I want them to thrive, and I believe that investing in their growth and encourage is worth it.