Based on Scripture (Matthew 1:18, Luke 1:27 and 1:35) and the
ancient creeds, Catholics hold that Jesus, the Son of God, was
conceived through the Holy Spirit and delivered of Mary, as
foretold by the angel Gabriel in the Annunciation, and that Mary
remained a virgin throughout her life. Marian scholars and
researchers write that Mary's virginal conception is a visible
sign of God's participation in the coming of Jesus and is not
intended as an anti-sexual message. Ordinary conception in
marriage is not less holy, they say.
There are several passages in the Bible that refer to the brothers and sisters of Jesus, and different explanations have developed to account for those passages. According to the Rev. Bertrand Buby, S.M., a Marian scholar and author, some Christian traditions believe them to be blood brothers of Jesus', others interpret them as cousins to Jesus and another group views them as children from a prior marriage of Joseph's. "The Catholic tradition is that Mary had no child other than Jesus," Buby says, and that brothers and sisters would refer to the extended family of Jesus, such as cousins. A more recent interpretation is that brothers and sisters refers to the larger company of believers and disciples.