He was one of the seventy-two disciples of our Lord, and was put in competition with St. Matthias to succeed the traitor Judas in the apostleship. St. Chrysostom remarks that St. Joseph was not displeased, but rejoiced in the Lord to see the preference given to St. Matthias. After the dispersion of the disciples he preached the gospel to many nations; and among other miracles, drank poison without receiving any hurt, as Papias, and from him Eusebius, testify. This saint, from his extraordinary piety, was surnamed the Just.
According to tradition, he went on to become Bishop of Eleutheropolis, where he died a martyr and is venerated as Saint Justus of Eleutheropolis. The location provides a date, since the site of Eleutheropolis was a mere village in the 1st century, whose inhabitants were slain and enslaved with others by Vespasian in AD 68.