For Simpson Fans...?!

does anyone know the name of the episode when there's a new kind of religion or something that takes over Springfield, and Lisa's the only one that doesn't give in!. I think the new religion had a leader named "big bro" or something, and they planned to go to a better place!. And, I think at the end, you see a flying saucer coming from the barn, but it falls apart and you see one guy paddling to keep the aircraft in flight!.
My memory is kind of hazy, but for the Simpson fans that know what i'm talking about, could you please give me the name of the episode!? Or even a list of possible episodes that I might be referring to!? Thanks a lot!Www@Enter-QA@Com

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