Late night comedian John Oliver recently delivered a harsh takedown of a group of televangelists who preach the "exploitive" Prosperity Gospel on his HBO program, "Last Week Tonight."

During the show which aired on Sunday night, Oliver acknowledged that the majority of churches nationwide are a "cornerstone of American life" and do good work in their communities, such as "feeding the hungry and clothing the poor."

However, he slammed pastors and "churches that exploit people's faith for monetary gain," mentioning in particular televangelist Creflo Dollar who asked his congregants this year to help him purchase a $65 million luxury jet, claiming that he needed it to better share the Gospel of Jesus Christ.

Oliver also took aim at Mike Murdock, sharing a clip of the prominent televangelist bragging in front of his congregation about purchasing two private jets with cash and telling his congregation to "act happy" about his "blessings."

The British comedian also shared video footage of televangelist Kenneth Copeland, who referred to his multi-million dollar private jet as a "preaching machine" used only for church activities but was found to be using it for trips to ski resorts and exotic hunting trips.

All three televangelists are among many who preach the "Prosperity Gospel" which Oliver says teaches "that wealth is a sign of God's favor, and donations will result in wealth coming back to you. That idea takes the form of 'seed faith' - that donations are seeds that you will one day get to harvest."

Oliver went on to address how the IRS is unable to to regulate the activities of these churches because the rules concerning religious organizations are so "purposely broad" and "a little vague."

"When you can operate with so little oversight, it is amazing what you are able to do," Oliver contended, revealing that he and his team corresponded with Robert Tilton's Word of Faith Worldwide Church for seven months to better understand what the televangelist is "telling people."

Initially, the comedian sent a donation of $20 to the ministry in January and asked to be added to the mailing list.

"Within two weeks, he sent me a letter back thanking me for my donation, and claiming, 'I believe that God has supernaturally brought us together,'" said Oliver.

Two weeks later, Oliver said he got an envelope back from the ministry with a $1 bill in it along with a message saying, "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 letter, colored oils, pieces of fabric in the shape of mountains and an outline of Tilton's foot.

One particularly exploitive letter among the 28 sent from the ministry included the line, "I must warn you not to rob God of your tithes and offerings."

"This is all hilarious until you imagine these letters being sent to someone who can't afford what he's asking for," Oliver contended. As a result of his findings, he decided to open his own church called Our Lady of Perpetual Exemption, a legally-recognized religious institution.

"It was disturbingly easy," said Oliver. They met some of the criteria without even trying: The IRS requires an "established place of worship." Well, "we meet every Sunday, in this studio in New York," Oliver observed.

"When John Oliver found out that Robert Tilton, Kenneth Copeland and other pastors of their ilk have been taking advantage of the open-ended IRS definition of the word 'church' and procuring a litany of tax breaks, he founded the Our Lady of Perpetual Exemption Church, a tax-exempt organization that you certainly can't say is not a church," notes the mission statement on the website for the church. "From that day forward, he has been dedicated to collecting copious donations and all manner of divine blessings, but mainly the donations."

However, if any money is in actuality send to the address provided on the website, the fine print notes that all donations will be sent to Doctors Without Borders.