This refers to special undergarments worn by those who have been initiated in the Mormon temple. The term “Mormon underwear” is most likely to be used by someone less familiar with Mormonism. The usual designation of “garments” or “temple garments,” comes from the phrase “garments of the holy priesthood,” referring to the clothing used in temple ceremonies.
Mormon underwear is made from cotton, polyester, or nylon in several variations. It is completely white, symbolizing purity. The first designs were one-piece garments, which are still available, but it is now more common to wear a separate top and bottom. The top is a T-shirt pattern, covering the shoulders and ending at the waist. The bottom extends from the waist to the knee. Mormon underwear is marked with symbols relating to the temple endowment ceremony. The design is to promote modesty and should be completely covered by outer clothing. Mormon underwear is worn directly next to the skin and replaces any other underwear. TheMormon Church manufactures and sells these garments itself, through Church distribution centers.
A Mormon will begin to wear this underwear as part of the initiatory ordinances of the Mormon temple ceremony. It is here that they will first put on this underwear and promise to wear it the rest of their life. It is symbolic of a covenant made with God, and the reverence that is shown in wearing these garments is evidence of the reverence toward the covenant made. Part of this reverence is not discussing the particulars of the temple ceremony outside of the temple where it may be (and is) taken lightly. This has brought about the incorrect assumption that the Mormon temple is “secret.” The Mormon missionary effort is evidence that Mormons desire everyone to believe and participate in temple worship, there is nothing secretive about it, but the temple is preserved as a sacred space separated from the profane world.
Part of the symbolism of Mormon underwear is biblical. The Lord clothed Adam and Eve with coats of skins when they discovered their nakedness. Modesty is one reason it is worn by believers. There is also mention of “holy garments” that Moses was commanded to make for Aaron (Exodus 28). In both of these occasions the special clothing is part of divine instruction and a sacred covenant. The faithful observer of this covenant is promised that it will become a protection to them. Contrary to the rumors that Mormon underwear is impenetrable armor, the promise is of a spiritual nature.
Although instructed to be worn at all times, there are practical considerations when Mormon underwear may be removed. Bathing is the most obvious. Likewise, swimming or vigorous physical activity may necessitate removal. It is not appropriate to remove or alter them to accommodate fashion. There is no official list; rather it is left to the discretion of the individual. The counsel is simply to wear them at all times unless it is deemed inappropriate to the activity, and not to find excuses to remove them.
Mormon underwear is a solemn religious act of symbolism showing a covenant between God and the wearer of it. Because of the sacred nature which is not discussed outside the temple, naturally, the curiosity of others is piqued. But there is nothing to hide. Mormon underwear is worn as a symbol and reminder of a covenant that person has made with God.