The Holy Apostle Jude, the Brother of the Lord, was one of the Twelve Apostles of Christ. According to Church tradition, he was the son of Righteous Joseph the Betrothed by his first wife and the brother of James. Though called the Brother of the Lord, he humbly identified himself as the brother of James and a servant of Jesus Christ.
After the Ascension of the Lord, Saint Jude preached the Gospel in Judea, Galilee, Samaria, Idumaea, Arabia, Syria, Mesopotamia, Edessa, and, according to tradition, Persia. He continued the apostolic work begun in Edessa by Saint Thaddeus of the Seventy and brought many people to faith in Christ.
The Apostle Jude left the Church a catholic epistle, calling Christians to keep the true faith, resist false teaching, persevere in prayer, and show faith through holy works. Around the year 80, he suffered martyrdom near Mount Ararat in Armenia, where he was crucified and pierced with arrows.
Saint Jude teaches humility, watchfulness in the faith, and steadfast love for Christ. His memory is celebrated on June 19 Old Style / July 2 New Style.
Source: Orthodox Church in America