The Testament of Gad, like the other Testaments of the Twelve Patriarchs, is considered to be a Jewish work that was added to by Christians in the Christian era. It is unclear when it comes from, however, fragments of the Testaments of Joseph and Levi have been found among the Dead Sea Scrolls in Aramaic, dating to between 135 and 37 BC, implying the rest of the Twelve were compiled at the same time. As the Testament of Gad includes a reference to Satan as a being, the text was neither a Sadducee or Pharisee text. Satan was also a being in the Book of Job, which is generally considered to be either a Babylonian or Persian era text, the Testament of Dan may also date to this time, and by extension the rest of the Testaments of the Twelve Patriarchs.
In the early Christian era, many Testaments of the Patriarchs circulated in Jewish and Christian communities, the foremost being the Testaments of Abraham, Isaac, and Jacob. The other major testaments were grouped together as the Testaments of the Twelve Patriarchs, which included the Testaments of Reuben, Simeon, Levi, Judah, Issachar, Zebulun, Dan, Naphtali, Gad, Asher, Joseph, and Benjamin. These testaments were widely accepted by the early Christian churches, and continue to form part of the Armenian Bible. The books were popular in Western Europe during the Middle Ages when they were generally considered authentic ancient Jewish texts. Critical analysis in the 16th century changed the view of Protestants and Catholics, as scholars at the time came to the belief that the texts were written in the early Christian era, likely in Greek. Subsequently, the texts fell out of favor in most parts of Europe. However, Hebrew fragments of the Testaments of the Patriarchs were discovered in the 20th century among the Dead Sea Scrolls, proving the texts were originally written in Aramaic and Hebrew. The current academic view is that there was a simpler Hebrew Jewish version that was then updated in the early Christian era by Greek speakers that added the Christian prophesies.
