There are three aspects of virginity: virginal conception, virginal parturition (giving birth), and perpetual virginity. Catholic belief is that Mary was a virgin before the birth of Christ, at his birth, and thereafter; in other words, she was always a virgin.

There is a scriptural evidence for the virginal conception of Jesus. In their conception narratives, both Matthew (1:18-25) and Luke (1:26-38) tell us that Jesus was conceived "by the power of the Holy Spirit", as we say in the Creed, and not through any human agent. Matthew is quite precise regarding the matter: "His mother Mary was betrothed to Joseph, but before they came to live together she was found to be with child through the Holy Spirit."

Luke emphasizes the point that since the Holy Spirit was to come upon Mary, the child conceived by her will have only a father in heaven, for he "will be called Son of God." In giving the genealogy of Christ, Luke makes it a point to say that Jesus was "thought" to be Joseph's son: "When he started to teach, Jesus was about thirty years old, being the son, as it was thought, of Joseph" (Luke 3:23).

The Gospels therefore clearly affirm that Jesus was conceived by the direct intervention of god and in a miraculous manner, which therefore excludes the normal procedure and preserves Mary's virginity, for, as the angel Gabriel assures her, "nothing is impossible to God."

Matthew goes further and quotes an Old Testament prophesy (Isaias 7:14) in support not only of the virginal conception but also of the virginal parturition. "Now all this took place to fulfil the words spoken by the Lord through the prophet: the virgin will conceive and give birth to a son and they will call him Emmanuel." Whatever the interpretation given by scripture scholars to this text from Isaias, what is important here is what Mathew wants to tell his readers, namely, that Mary remained a virgin in conceiving the divine child as well as in giving birth to him.

As for Mary's perpetual virginity, although Ezekiel 44:2, viz., "This gate will be kept shut. No one will open it or go through it, since Yahweh the God of Israel has been through it. And so it must be kept shut" has been interpreted by some medieval scholars and theologians in support of Mary's perpetual virginity, it is a Christian tradition that assure us of it. We have to note, moreover, that it cannot be argued from the New Testament reference to the 'brothers' and 'sisters' of Jesus that Mary had other children for they were no more than cousins or close relatives.

Tradition regarding Mary's virginity has existed from very earl times. St Ignatius of Antioch, very much of the first century itself (he died at Rome C.107), in his letter to Smyrna, says that Jesus was "truly born of a virgin", thus affirming both virginal conception and virginal parturition. This indeed is very early evidence from tradition. Patristic affirmation of Mary's virginity has been constant all along and it reflects the belief of the faithful from very early times. This belief may be summed up in the words of St Augustine (354-430): "She conceives, and is a virgin; she gives birth and is a virgin. "Not long after, this traditional belief of the Church was unanimously accepted by the Ecumenical council of Chalcedon (451).

The expression 'ever-virgin' as applied to Mary has been current in the Church from early centuries. In the 4th century, St. Epiphanius (c.315-403) introduced it into the eastern version of the Nicene Creed. Vatican II reaffirms it in the words of the canon of the Roman Mass, "the glorious and perpetual Virgin Mary, Mother of our God and Lord Jesus Christ" (Dogmatic Constitution on the Church, 52). These words come in the present Eucharistic Prayer I as "We honour Mary, the ever-virgin mother of Jesus Christ our Lord and God."