It is because they are married to God and so, seeing as they cannot have physical sex with God, do not have sex at all.
However, the blanket statement of all nuns being virgins is not necessarily true. Once a woman becomes a nun, she is to remain chaste. This does not preclude a woman from being married, raising a family and becoming a nun when her husband dies. Sister Elizabeth Ann Seton (now Saint Elizabeth Ann Seton) is a good example.
Because a nun is supposed to be entirely devoted to Jesus, and not to muck about with human males.
Yes, non-virgins can become nuns. However, once a nun they must remain celibate.
No. In the process of becoming a nun a woman takes a vow of abstinence (promise to not have sex), but having had sex in the past does not prevent them from coming nuns in the future.
Roman Catholic AnswerBefore Vatican Council II there was a separate rite for receiving a woman into the convent who was not a virgin, say a widow. I don't know if this is still the case or not. So this is not necessarily a requirement.
The Virgins was created in 2005.
According to the Catholic Encyclopedia Nuns or Sisters evolved in the first century.http://www.newadvent.org/cathen/11164a.htm"The institution of nuns and sisters, who devote themselves in various religious orders to the practice of a life of perfection, dates from the first ages of the Church, and women may claim with a certain pride that they were the first to embrace the religious state for its own sake, without regard to missionary work and ecclesiastical functions proper to men. St. Paul speaks of widows, who were called to certain kinds of church work (1 Timothy 5:9), and of virgins (1 Corinthians 7), whom he praises for their continence and their devotion to the things of the Lord.""Virgins vowed to the service of God, at first continued to live with their families, but as early as the end of the third century there were community houses known as partheuones; and certainly at the beginning of the same century the virgins formed a special class in the Church, receiving Holy Communion before the laity."
Blood of the Virgins was created in 1967.
Revenge of the Virgins was created in 1959.
In the Bible Exodus 22:16, it talks about the dowry of virgins: what was included in the dowry of virgins
Other nuns
No They're Aren't Virgins.
The duration of Property Virgins is 1800.0 seconds.
Property Virgins was created in 2006-03.