Eusebius also reports the tradition that James the Just was the son of Joseph, and therefore the brother of Jesus (as well as Jude) mentioned in Matthew 13:55, Mark 6:3, and Galatians 1:19. Paul further describes James in Galatians, with Cephas (better known as Peter) and John, as one of the "pillars", and who will go preach to "the circumcised" (that is the Jews) while Paul and Barnabas will preach to the Gentiles (2:9, 2:12). James's relation to Jesus has been problematic to many Christians due to the belief that Jesus Christ was the Son of God, and James the Just would therefore be at best a half-brother or a step-brother. See Christology.
James the Just is sometimes given credit for writing the New Testament book the Epistle of James, although it has also been ascribed to James the Great and James the Less. He was also traditionally believed to be the author of the Protevangelion of James, or "Nativity Gospel of James", though modern scholars date this document to the 2nd century.
On June 18, 2003, the Israeli Antiquities Authority published a report concluding that the inscription containing the Ya`aqov bar Yosef akhui di Yeshua` (James son of Joseph brother of Jesus) on an ossuary is a modern forgery based on their analysis of the patina. Specifically, it appears that the inscription was added recently and made to look old by addition of a chalk solution. The ossuary came to light in 2002 under questionable provenance and was thought by some to be historical evidence for Jesus's brother James. The dealer, Oded Golan, has been arrested and found to have forgery equipment and partially completed forgeries.