"Whoever does the will of God is my brother, and sister, and mother" - Jesus (Mark 3:35).
"Their first lawgiver [Jesus] persuaded them that they are all brothers and sisters of each other after they have transgressed once for all by denying the Greek gods." - Lucian of Samosata (The Passing of Peregrinus, 2nd century C.E.)
If one of Pauls contemporaries could time-travel to the 21st century and read popular English translations of his letters, puzzlement would surely provoke some questions: "Why in so many passages has the Greek word for brothers been mistranslated using non-family terms? Dont the translators know that Pauls favorite way of referring to us was as his sisters and brothers? Why has one of the most important features of our new identity in Christ been hidden from these English readers?"
Jesus is remembered by both friend and foe (as in comments by Mark and Lucian, above) to have redefined the basis and limits of family life, rejecting blood ties in favor of the faith-based sibling-like bond that he created among his followers. Persons who do Gods will have become Jesus siblings with God alone as their parent (see Mark 3:35, Matthew 12:50, and Luke 8:21). Most English translations of the gospels do faithfully report that fact. Yet this translational accuracy disappears in many English versions of Pauls letters.