Mark 6:3
Is he not the carpenter, the son of Mary, and the brother
(adelphos) of James and Joses and Judas and Simon?
And are not his sisters (adelphai) here with us?
First it is important to note that the Bible does not
say that
these "brothers and sisters" of Jesus were
children of Mary.
Second, the word for brother (or sister), adelphos
(adelpha)
in Greek, denotes a brother or sister, or near
kinsman. Aramaic
and other Semitic languages could not distinguish
between a
blood brother or sister and a cousin, for example.
Hence,
John the Baptist, a cousin of Jesus (the son of
Elizabeth, cousin
of Mary) would be called "a brother (adelphos)
of Jesus." In
the plural, the word means a community based on
identity of
origin or life.