At a recent family gathering, my younger brother said he had led the Seder during Passover this year. He explained that he'd been present the last several years, but this was his first time leading. (I think it was also at his home.)
My understanding (from reading here and elsewhere) is that he would need to have converted to Judaism before he could do that. But he (and his wife) also talked about a trip they're taking to Israel this summer, and specifically said they were doing it as non-Jews.
Please help me understand where I might be wrong, where my assumptions lie, and/or what I'm missing.
Edited to answer questions from the comments:
Are we Jewish? No. We grew up attending a Presbyterian church, and as far as I know, he still attends.
What did he mean by "leading"? He was somewhat vague about what "leading" meant; he said something like, "It's really a whole ceremony. There are things you say and talk about, then you share that type of food, and then there are other things you say and talk about."
Edited again to add:
Thank you for the kind responses so far. I suppose my real question is whether he has become so devoted to the idea of Israel that he's discarded any respect for the Law.