There is a small, but influential group that's been operating inside the Catholic Church for over 75 years known as Opus Dei.
It is a private, some say secret, organization within the Catholic Church. Its 85,000 members in 60 countries make up a personal prelature who was held in high esteem by Pope John Paul II.
Opus Dei recently gained some negative publicity with the publication of Dan Brown's "Da Vinci Code." While the book is a work of fiction, it makes numerous claims about Christian history and theology, including that Jesus and Mary Magdalene were married, and that Leonardo da Vinci hid secret messages and symbols in his works. And then there is that albino monk sent by a secret Catholic society called Opus Dei to rub out several of the characters in the novel.
Cartoonish villains aside, Opus Dei does indeed exist. Meaning "work of God," the group is an important and influential part of the Catholic Church. It was founded in 1928 by a Spanish priest, a man later canonized by Pope John Paul II in 2002.
"The work of Opus Dei doesn't need to be publicized," explains MSNBC analyst Msgr. Thomas McSweeney. "The recognition, they maintain, is in the work itself—the work of God and at the attempt at holiness in everyday activity."
There's a long history in the Catholic Church of personal sacrifice or penance, like for example, abstaining from meat on Fridays, or fasting on occasion.
But some followers of Opus Dei take their sacrifice to a deeper level by practicing "corporal mortification," or physical punishment of their own body. Msgr. McSweeney explains corporal mortification as something associated with spirituality and piety. "That's flagellating yourself, fasting to the extreme and so forth. The reasoning is so that you can keep yourself focused. But with Opus Dei, that's generally been an exaggeration. There's really no corporal mortification there. There maybe one or two people who practice it, but their practice of piety is more what they would call 'self-denial.'"
The modern Opus Dei is still mostly shrouded in secrecy, but it does have a Website that describes much of its history and its mission. Pope John Paul II was particularly fond of Opus Dei, designating it a personal prelature— meaning that it operates with little oversight by bishops.
And because of its power, influence and high-profile members around the world, the group continues to have close ties to the Vatican, and, most likely, the next pope.
According to Msgr. Sweeney, "There are cardinals who are members of Opus Dei. There are some who understand the work of Opus Dei. But I don't believe that the conclave as a collective body would be persuaded by one particular entity."