Someone in the comments asked about the Travelling Lutherans, and I thought I would give the ending to that story.
The Lutherans stayed with us that night, and we fed them, watched Guardians of the Galaxy together (as is proper) and put them up in our parish hall. They ate breakfast and vamoosed in the morning, bright and early.
A few weeks later, I received a really lovely letter from their pastor in Wisconsin thanking me and the parish for our hospitality, which was cosigned by all the kids who had visited. It was very sweet.
And truthfully, this is how formation works. It happens in the meticulously-planned programs, and the expensive mission trips and the curriculum we agonize over, but mostly, the things that stick are the small moments in between, when children watch adults make decisions on the fly. Hopefully, these kids will remember this one.