Q: In the Catholic Revised Standard Version of the Bible, there appears to be an error in Luke 6:16 and Acts 1:13 in speaking of “Judas the son of James.” The Douay Version, however, speaks in Matthew 13:55 about “Jude the brother of James.” Why?
A: The passages you cited do not contradict one another because they probably refer to three separate people. I often refer biblical questions to Father Hilarion Kistner, O.F.M., who has a doctorate in theology with a specialization in Scripture. He responds that the Greek for both apostles is Ioudas and is properly transliterated as Judas.
However, because of the notoriety of Judas Iscariot, some English translations use “Jude” for the good apostle and “Judas” for the one who betrayed Jesus. In John 14:22, the New American Bible speaks of “Judas, not the Iscariot.” So do other translations.
The Douay text in Matthew 13:55 lists Jude as among “the brethren” of Jesus but not as an apostle.
The footnote there says: “These were the children of Mary the wife of Cleophas, sister to our Blessed Lady (Matthew 27:56 and John 19:25) and therefore, according to the usual style of the Scripture, they were called brethren, that is, near relations to our Saviour.”
The Church has never understood any of the 12 Apostles as being related to Jesus by blood.