Please note: the following is meant for humor, not to offend.
1. Mormon underwear, Mormonism
Of the many quirky facets of the Church of Latter Day Saints, "Mormon underwear" is probably the most notable. No other sect of Christianity prescribes any article of clothing, to the best of the ULC's knowledge, and the fact that Mormonism's de facto uniform happens to sound like a holy chastity belt is much derided by non-LDS members.
The Universal Life Church Monastery staff were a bit skeptical about the common perception and prevalence of Mormon underwear while writing this article, and thus wanted to hear directly from a Mormon what these holy garments are all about. Eric, a helpful missionary who fielded our queries on mormon.org's live chat system, enlightened us.
"Temple garments", according to Eric, are special pairs of both shorts and briefs that are Mormons' "outward expression of the inner commitments [Mormons] have towards Christ".
Specifically, wearing Mormon underwear shows a "[willingness] to help build God's kingdom" through "obedience to what [Mormons] call the Law of Chastity".
When asked if he was wearing Mormon underwear during our conversation, Eric said "Yeah. Always".
2. Snake handling, Christianity
While many Christians choose to use prayer, communion, and baptisms to get closer to God, a subset of the Pentecostal church believes that handling snakes is a great way to enhance one's faith. This practice, which is supported by a mere three passages from the Bible, is gaining ground in the American Southeast and has appeared as far away as Canada in the last decade.
The most peculiar part of this exercise of faith are the varieties of snakes used; while non-poisonous serpents would presumably suffice, snake handling churches frequently employ deadly rattlesnakes. It is for this reason that many leaders of snake handling churches, including the founder of the first of such churches in the US, have met their maker from fatal snakebites. Such practices undoubtedly merit a Darwin Award and not His blessings.
3. Blood and Body of Christ, Christianity
Many Christian sects ingest a bread wafer and wine during Holy Communion. The bread symbolizes the body of Christ and the wine represents the His blood. The primary purpose of Holy Communion for Christians is to give thanks and remembrance to their Lord and Savior.
We at The Universal Life Church Monastery understand that cannibalism is an illegal practice in most of the world and though symbolic this regularly-practiced Christian tradition is a bit weird, but mmmm bread and wine do go well with together.
4. Circumcision, Judaism/Islam
Germany (http://www.guardian.co.uk/commentisfree/belief/2012/jul/17/german-circumcision-affront-jewish-muslim-identity) may currently be recoiling from the practice of lopping off young boys' foreskins but perhaps Jews and Muslims are onto something. A recent study stated that circumcision results in a less sensitive penis. Whether that's a good thing or bad is for you to decide. Also, who's to say that the baby doesn't want their foreskin.
5. Self-Flagellation Parade, Shiite Islam
This Shiite practice involves whips, a crowd of god-fearing men and a lots of pain. Every year, Shiites commemorate the martyrdom of Hussein, a member of Muhammad's household and an imam, with a mass flogging that is supposed to literally beat the hell out you.
6. Exorcism, Catholicism
Fun fact: The Exorcist, a 1973 horror film involving the possession and exorcism of a 12 year old girl by an ancient Babylonian demon, is (more or less) factually accurate.
This claim was made by Gabriele Amorth, an Italian priest and the Catholic church's "chief exorcist". Father Amorth claims to have performed over 70,000 exorcisms during his lengthy career, up to 10 a day at his peak.
Despite his fervent belief that demon possession is real and exorcisms are a valid aspect of Christian faith, Amorth, who has been a priest in one of the most powerful institutions in the world for almost six decades, nevertheless claims that the Harry Potter books and yoga are satanic in nature and should thus be avoided at all costs.
7. Appeal to Celebrities, Scientology, Universal Life Church
Celebrities Tom Cruise, John Travolta, Beck, Sonny Bono and Kirstie Alley are or previously were members of Scientology, a newly-emerged religion divined by science fiction writer L. Ron Hubbard. Scientology may get a lot of criticism but if you have Kirstie Alley as a celebrity endorser you can't go wrong...sorry Jenny Craig. In fairness, we're not above this ourselves - we love seeing famous faces join our cause.
8. Naked Man Festival, Shintoism
What do copious amounts of sake, thousands of loincloth-wearing Japanese men, and Japan's indigenous spirituality have in common? The Naked Man festival, of course. The highlight of this festival is when the specially selected "Naked Man" runs through the streets of town, stripped of his clothing and shaved of his body hair, while being pursued by thousands of other men hoping to chase him down and touch him for good luck.
9. Blood and Body of Christ (Cont), Catholicism
Catholics have taken the symbolism of the Eucharist ceremony one step further by swearing that they are "literally" (http://www.newadvent.org/cathen/05573a.htm) consuming the blood and body of Christ. This process is known as Transubstantiation and is considered somewhat of a miracle. Changing wine into Christ's blood and bread into the Christ's body does sound like a miracle but is definitely not as appetizing as the more mainstream form of communion.