We just got a letter from my wife's church friend who is asking for support for a one week mission trip to New York City. She was surprised and offended when I objected. Supporting a mission trip is like supporting someone's vacation. It is a waste of time, money, and effort.
When donating money, you should ask, "what's the return on investment?" For instance, I could send money to Doctors Without Borders and expect a large portion of my money to pay for healthcare supplies in developing countries. Cool.
What is the return on investment for a mission trip? The money would pay for a vacation. Period. No one would be helped from this experience besides being fed lies to provide a false hope in what is to come.
Sure, there are some missionaries who do actually help people and I could see myself supporting a missionary if their mission was more secular than religiously motivated.
I thought about sending this friend some money and then sending her family a letter asking for funding to complete my master's program. I am a teacher and my masters program should mold me into a better teacher which can positively impact the science education of 1000s of kids over my career. I like that return on investment much more than a mission trip vacation