Were all the disciples Jewish? There seems to be some controversy whether Luke was a Jew or a Gentile.
All the original disciples were Jewish, but Luke was not one of the 12. He was Paul’s companion and personal physician. He was also assigned the role of Paul’s historian and his authorship of the gospel of Luke and the book of Acts were for that purpose. Personally, although the Bible doesn’t specifically identify Luke as being Jewish, I think those who claim that he was have a more compelling case than those who believe he was a gentile.