What good is short-term missions?

Recently I had a great conversation with someone who has never been on an international missions trip and has only participated in one local mission trip during her wonderfully extensive life. She was being very open and honest when she asked me why she should consider supporting church members who went on short-term missions - was it really worthwhile? I really appreciate her deep consideration and her honesty. We need more of it in the church! We should never - I repeat never - assume that any church body, any church leadership, any church tradition is automatically Biblical because it is under the "roof" of the church. That assumption has led to so very many cultural mistakes, completely false teachings, and unnecessary divergence from God's absolute truth.
So yes, I DO appreciate her honesty and her questioning. In fact, at one point earlier in my life I had wondered the same thing but did not verbalize it! Why should we spend time, money and energy on short-term missions? Why not simply focus on evangelizing our neighborhoods and supporting missionaries in other cities and countries?
When Jesus wanted to teach people he used parables. There is nothing more permanently thought-provoking than a good parable. Why? With it we change lenses in our worldview glasses, swap out our prejudices for new ideas, and end up right back at home re-evaluating ourselves and our actions in a different way. Short-term missions is, in a way, a "reality parable". Yes, hopefully we will encourage career missionaries. Yes, we have the opportunity to reach people simply with the curiosity factor invoked who might not otherwise come to hear the one and only true life-changing Good News story. But more importantly, I think, is the fact that the trip is a parable that we bring back home with us. A new way of looking at familiar surroundings that might, and often does, bring us to the realization that we need only to open our eyes as far as the mirror before we see someone who needs a Savior. And then we can see our families, our next door neighbors, our coworkers and fellow church members as mission fields, too - fellow sinners in need of Christ. We often set out to be used by God for others in a new place and find out that He has used His own love to change our hearts. Then finally, maybe, we will see that the whole idea of missions is not about us, or missionaries, or even the lost of other places, but about Christ. And if we can see HIM at the center, it will not matter where we are, where we go or what we do. Anything and everything with Christ alone at the center is always worthwhile.