Dr. Martin Luther King Jr. wrote a paper on the subject: "The Ethics of Late Judaism as Evidenced in the Testaments of the Twelve Patriarchs".
The writings consist of the last words and exhortations of the twelve sons of Jacob to their Children. Each testament indicates the virtues inculcated or the vices condemned by each of these patriarchs in turn.
However, it seems the main text of the Testaments of the Twelve Patriarchs was written during the intertestamental period, and then subjected to heavy editing during the first and second centuries.
I would like to know what Catholic, Orthodox and Protestant denominations make of these writings and whether they are considered to be authentic and reliable.
I honestly don't know which tags to apply to this question, so I welcome any helpful suggestions.