Jesus' Siblings
There are two traditional ways of understanding who the Scriptural “brothers” of Jesus were. According to one tradition, rooted in the Protoevangelium of James, these “siblings” are from Joseph's prior marriage (because Joseph was a widower). This perspective is the standard explanation found in Eastern Orthodox Churches.
Roman Catholic theologians, on the other hand, have been more inclined to say that that these siblings were cousins. This statement is based in the teaching of Saint Jerome, a Biblical scholar who didn't like the way the Protoevangelium of James described the siblings of Jesus as stepbrothers.
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Saint Jerome preferred the argument that the siblings of Jesus were cousins because he felt that it was most appropriate for both Mary and Joseph to have been virgins. Saint Jerome felt that it would have been improper for Joseph to have fathered other children even if he did remain chaste with Mary.
Ever since Jerome's statement, Roman Catholic theologians have been more inclined to emphasize the Pseudo-Gospel of Matthew, a later text that shares many elements with the Protoevangelium. According to the Pseudo-Gospel of Matthew, the siblings of Jesus were actually his cousins. The pseudo-Gospel of Matthew is also distinct in that it offers more information about Mary's education in the temple. Stories from the Protoevangelium became popular in the West many years later, when they were incorporated into The
