I think the basic issue is one of expectation and transparency. The people who gave you money wanted you to have a helpful mission experience this summer. You trusted the Lord, and He generously supplied, as He so often does.

However, you also have school expenses, and you are forgoing the opportunity to work and gain money for next year’s studies. I am sure that those who gave you money for your trip would also be delighted to see you use any extra to help you further your education.

My suggestion would be that you just tell it like it is. Write your supporters a letter, thanking them for their kind and generous contribution to your trip. Mention that you feel the Lord surprised you with more than you need, and you would like to ask their permission to use these funds as a small partial scholarship for next year’s school expenses, recognizing that you gave up the opportunity to work so that you could obey the Lord by going on this mission trip. You may add that if this is a problem with them, that they should write you.

I am quite confident that all will be in accord with your suggestion. If they are not, of course, you may have to figure out how to reimburse them.

Actually, both your formal schooling and your mission trip are part of your general education. However, people who contribute have a right to know where their money is specifically being invested and that the desires of the donors of designated funds be honored.

How to work out the details of those who may object may be a bit complicated. It all depends who is receiving and handling the funds. However, this would be my suggestion, and you will have to check with those handling the funds as to how this may actually be worked out.