On last night's episode, Barb returned to the LDS to receive her Endowment, a super-sacred ceremony that's intended to be "secret from the world," which is why HBO's reenactment of it was so controversial.
Before I get started, I'd just like to say that I personally believe that all organized religions are weird, including the one I was raised in, which told me that I had to eat a piece of someone's body and drink his blood once a week, and fess up to all the bad things I'd done and thought to a man hidden in a little cubby hole. Rituals always appear odd to those who haven't grown up with them.
But that's also because rituals are often odd, especially when they're shrouded in secrecy. So when we got to see the Freemason-esque LDS Endowment ceremony, the secret handshakes, the costumes, the props, and the Celestial room, it was a bit jarring. Perhaps it's because Mormonism is a fairly young religion founded by pioneers — who, in fact, were Freemasons at one point — this makes their practices seem bizarre to outsiders. And that's may be why Mormons guard them so carefully.
Church members aren't even supposed to discuss the ordinances of the Endowment outside of the temple, and until as recently as 1990, part of the ceremony included a "blood oath," in which members promised that they understood that they'd be disemboweled or have their throats slashed if they revealed any of the secrets of the ceremony. That's why some LDS members are upset with the Big Love episode, and why Barb's mother was so reticent to "monkey around" with Mormon procedure by allowing her polygamous daughter to access the temple through her recommendation.
The LDS takes the Endowment very seriously because it reveals to members key words and tokens they need to pass by angels guarding the way to heaven. Barb was facing a disciplinary hearing and excommunication for being involved in plural marriage. Excommunication to Mormons means much more than being banned from the church on earth. It means they're banned from entering the Celestial Kingdom after death, and cast into the "outer darkness" for all eternity. Fearing this, Barb had to beg her mother and sister to give her a temple recommend in order to receive her Endowment, as an of-chance way to gain entrance into heaven.
In the end, Barb was excommunicated from the LDS because of her plural marriage, but more importantly, because of her knowledge of the LDS's purchase of an official letter that stated that the church never intended to outlaw polygamy, and the LDS's intention of hiding the letter from the public. This storyline makes the church look incredibly corrupt; I wonder if they're as pissed off about that as they are about the depiction of the Endowment ceremony.
During her hearing, the church officials asked her if she was wearing her "temple garments," which are special underwear to be worn under the clothes.
According to Wikipedia, FLDS members wear something similar under their clothes, but a little more modest and more like the original garments that the founding members of the church wore. These garments, among other things, make me wonder if FLDS members aren't as different from some mainstream Mormons as LDS members would have us believe. They just fly their freak flags more publicly.