(This is the real, honest to goodness, straight from the horse’s mouth poop on what it’s all about folks!)
The Galactic Federation of 76 planets, founded 95,000,0000 (million) years ago, was suffering from overpopulation.
Their leader, Xenu, took all the ‘Billions’  of people who were not needed or wanted, and brought them to Teegeeack (Earth) where he threw them into volcanoes and then H-bombed them!
For his crime, loyal officers of the people captured him after 6 years of battle, and put him in a mountain trap where he is still locked up to this day!
And, this is what their MANTRA goes like: (Sung to the tune of the ‘hokey pokey!’)
“You put the people in and take the h-bombs out!
Throw ‘em in the volcano, and then we shake it all about!
We do the hokey pokey and we blow them all to hell.
Then we get more people so we can do it to them as well!
Always remember, boys and girls, rumour has it that Scientology was started as a bar bet between L. Ron Hubbard and Robert Heinlein that there was more money in religion than in writing science fiction! (Which is what Hubbard did for a living!)

On a personal note, I briefly became involved with Scientology in the late sixties, but had the good sense, or good fortune, to recognize it as a scam and got the hell out. I was in the Canadian headquarters in Toronto when Ron Hubbard was visiting from his yacht in the Caribbean, (Sea Org) and I overheard him talking to the guy running the local show. I don’t know the exact content of the discussion, but what I did hear was the local guy saying to Hubbard; “Common Ron, we can’t tell them THAT! They’re not completely stupid you know!”  To which Hubbard replied………..!
“Well, let’s just see how stupid they really are!”
That was the day I decided I had enough of Scientology…, and religion in general!