Luke 9:46-50: in context

Two arguments happen back to back among the disciples, and Jesus treats them as the same problem. The first is a dispute about which of them is the greatest. Jesus answers it by setting a little child beside him and saying that whoever welcomes this child welcomes him, for the least among them all is the one who is great. He turns their ranking upside down: greatness is found by going low, not by climbing over one another.

Then John, apparently missing the point entirely, brings up the second matter, and it is the flip side of the same coin. Master, he says, we saw someone casting out demons in your name, and we stopped him, because he does not follow along with us. There it is: not one of us. The disciples wanted to be highest inside the group, and now they want to police the boundary of the group, shutting down a man who was doing genuine good, freeing people in Jesus's own name, for the sole crime of not belonging to their circle. And Jesus corrects them as plainly as he can. Do not stop him, he says, for whoever is not against you is for you. Someone doing God's work outside your camp is not your rival; he is on your side. It is the same lesson Moses had taught long before, when Joshua wanted to silence two men prophesying outside the tent and Moses said, would that all the LORD's people were prophets. The instinct to guard turf, to rank ourselves above and fence others out, is exactly what Jesus keeps dismantling.

The disciples tried to shut down a man doing good in Jesus's name because he was not one of their group. Whose good work, done outside my circle or tradition, do I quietly resent or dismiss, when Jesus would say he is for me, not against me?