Comedian John Oliver dedicated Sunday night's edition of his US TV show Last Week Tonight  to taking down American televangelists who manipulate their audiences into giving them money. He even set up his own "church", Our Lady of Perpetual Exemption, inviting donations via its website.

John Oliver – who he?

If you asked that question in America, people would think you had been living on the moon. He's a British comedian who appeared on Mock the Week before making it big in the States, joining The Daily Show. His great-great-grandfather was the Bishop of Ripon.

Well, that's me told. What's his point?

Oliver targets televangelists who preach "seed faith", the idea that if you give money to them God will send you lots more in return.

Like a guaranteed Lottery win?

A bit more spiritual than that, but yes, that's the general idea. Oliver prepped for the show by sendng televangelist Roger Tilton $20. He got a letter back containing a dollar and instructions to "Send it back to me with your best Prove God tithes or offering." "That's right," said Oliver, "I had to send the $1 back with an additional recommended offering of $37, which I did. So at this point, we're just two letters in and it's like having a pen pal who's in deep with some loan sharks." Oliver continued to send money ($319 total), receiving in return pieces of fabric in the shape of mountains and an outline of Tilton's foot.

Tilton sounds dodgy. Anyone else?

Oliver references people like Gloria Copeland, who advises people with cancer that going to church and donating money is more likely to get them healed than chemotherapy. He also talks about the notorious Creflo Dollar, who asked his followers for $65 million to buy a jet, and lots of others. Kenneth Copeland has a jet too, which he calls a "preaching machine"; he uses it to go hunting with his son. Oliver calls him a "reverse Noah," killing animals two by two. There are lots of others, it's quite a thing.

Does it work?

What do you think? "As an investment, you'd be better off burying your money in the actual ground," said Oliver, "Because at least that way there is a chance your dog may dig it up and will give it back to you one day."

But it can't be legal, surely.

Bizarrely, as Oliver shows, it is. That's because the US Internal Revenue Service "makes no attempt to evaluate the content of whatever doctrine a particular organisation claims is religious, provided the particular beliefs are truly and sincerely held and the practices are not illegal".

And is Oliver's church a real church?

It depends on what you mean by church. According to the IRS, yes. On its website he describes Our Lady of Perpetual Exemption as "a tax-exempt organization that you certainly can't say is not a church". It has a genuine donations hotline, though it says that it may close down shortly and that it will give any assets to Doctors Without Borders.

So a better question might have been, are these televangelists' churches real churches?

I couldn't possibly comment.

Oh, all right. Some of them are deluded, misled by a naively uncritical reading of passages like Malachi 3:10, where the prophet urges the people to "bring the whole tithe into the storehouse" and God will "throw open the floodgates of heaven and pour out so much blessing that you will not have room enough for it". Most of them are parasites who are driven by a devouring love of money, conscienceless leeches who drain gullible people of money they can't afford in order to fund lifestyles that their victims can only dream of. Acts 8:9-24 tells the story of Simon Magus, who tried to buy the gift of conferring the Holy Spirit from the Apostles. Peter said: "May your silver perish with you, because you thought you could buy the gift of God with money!...Repent of this wickedness and pray to the Lord."

I quite like the idea of setting up my own church, though.

Really?

We'd only sing hymns, not modern worship songs. No children, they make too much noise. Decent coffee...

Just stop.

Follow @RevMarkWoods on Twitter.