Before we can understand this question, we first need to understand how the Biblical canon was formed. The early church was compelled to define the New Testament canon in response to the Marcionite heresy. Marcion was an influential church leader in the second century who spread a form of Gnostic heresy, claiming that God the Father was an evil deity opposed to Jesus, the true God, and claimed that Christians should reject the Old Testament, and pronounced that only the Gospel of Luke, Acts, and the ten main Pauline Epistles, excluding the later pastoral epistles, could form the New Testament canon.
Marcion was declared a heretic, and the church started the centuries long process of determining which writings would form the Christian canon, the final consensus was not finalized until the fifth century. Most Christian leaders agreed that the four Gospels, Acts, and the Pauline Epistles would be canonical. There were debates over whether Hebrews, the shorter Epistles of Jude, John, and Peter would be included, and Revelations was the last book to be admitted to the canon by universal consensus. The early church historian Eusebius, living in the time of Emperor Constantine, is a valuable source for the consensus on the canon in the early fourth century.
There were several writings of the second century Apostolic Fathers that many communities had accepted as Scriptural, including them in their local canons, that were not included in the universal canon. The consensus formed that writings accepted in the canon had to meet these criteria:
- The author should be one of the first century apostles.
- The writing had to teach orthodox doctrine.
- The writing had to be accepted by many Christian communities.
Some of the writings that were included in the canon of some Christian communities but were not included in the final canon included:
- Epistles of Clement to the Corinthians: Eusebius states that “Clement’s epistle was read aloud to the assembled worshippers in early days, as it is in our own.” Although the teachings are orthodox, Clement was a second century bishop, and thus was not apostolic.
- Epistle of Barnabas: Although the authorship was attributed to the apostle Barnabas by the early church, and many local churches held it in high esteem, it was not accepted as canonical by consensus, which is fortunate since it contains many explicitly anti-Semitic teachings.
- Shepherd of Hermas: Many early church leaders, including Irenaeus, considered Hermas to be an apostle, but Eusebius informs us that though many churches thought it was beneficial for converts to study, there was little push to include it in the formal canon, likely because it teaches rather simplistic doctrines.
Although the early Church by consensus had set the canon of the New Testament, there had never been a need to formally set the canon of the Old Testament until Luther challenged the canonical status of the Catholic deutero-canonical books, which were called the Apocrypha by the Protestants.
The Church Fathers differed on what should be included in the Old Testament canon. St Jerome, who had updated the Latin translation of Scriptures in the Vulgate, preferred a narrow canon including only the Hebrew books of the Jewish canon, following the preference of most rabbis.
The early Greek books that had no extant Hebrew original were included in the Septuagint, a Greek translation of the canon from the second century BC in Alexandria. Linguists initially suggested that the Greek translation was inferior to the “original” Hebrew original, but some scholars who have studied the Dead Sea Scrolls have argued that the Septuagint was actually a translation from another Hebrew manuscript family that has since been lost to history.
The rabbis held the council of Jamnia somewhere in Palestine in the first century after Christ and this council discussed the canonicity of several books, including, according to Wikipedia, the Song of Solomon, which is basically a Persian love poem. Many modern scholars suggest that this council did not actually suggest a list of canonical Old Testament books, the scholar Lewis is quoted as saying, “The Jamnia hypothesis should not be allowed to be considered a consensus established by mere repetition of assertion.”
Which is applicable advice for modern listeners, you just cannot judge the accuracy of a YouTube video based on the number of views the channel attracts.
The Church Fathers differed on what should be included in the Old Testament canon, St Jerome, who had updated the Latin translation of Scriptures in the Vulgate, preferred a narrow canon including only the Hebrew books of the Jewish canon. St Augustine preferred the wider canon which included the deutero-canonical books written in Greek, which are called the Apocrypha by Protestants. St Jerome and St Augustine were contemporaries, they often corresponded with each other.
The delegates at the Council of Trent really did not want to decide between the positions of St Jerome and St Augustine, so the official decree simply lists the books of the wider canon, which meant that Trent adopted the position of St Augustine by default. Since the popes sealed the proceedings of the Council of Trent, not making them available to scholars until the 20th century, the actual conciliatory position of the Council proceeding was not recognized until then.
Luther preferred to exclude the deutero-canonical books since several are problematic according to his slogan, sola scriptura, or Scripture Alone: Tobit and Judith are both clearly fictional and not historical, and Maccabees exhorts us to pray for the dead, which Catholics claim as support for the doctrine of Purgatory, which Luther rejected.
What books were in the Apocrypha, which Catholics refer to as the deutero-canonical books? You can see from this list that the Protestant Apocrypha includes books seen as canonical for both the Catholic and Orthodox Churches, while the Eastern Orthodox Church includes some additional works in their canon. Plus, the Ethiopian Orthodox Church has a few more writings in their canon that we did not list.
Canonical for the Catholic Church and the Eastern Orthodox Church:
Tobit, Judith, Baruch, Wisdom of Jesus: Son of Sirach,
1 Maccabees, 2 Maccabees, Wisdom of Solomon
Additions to Esther, Daniel, and Baruch
Canonical only for Eastern Orthodox Church:
Prayer of Manasseh, 1 Esdras, 2 Esdras, Psalm 151,
3 Maccabees, 4 Maccabees as an appendix
Included are two wisdom books that are similar to the book of Proverbs, plus the excellent histories of the Maccabees, the Jewish rebels who managed to form an independent kingdom of Israel, and how they were conquered by Rome, leading to the martyrdom of the Maccabees.
The Book of Tobit is a delightful story beloved by Catholics, it has a story where an angel appears to the newlywed couple on their honeymoon to protect them from the demon that threatens them.
Quoting from the Book of Tobit:
“When the parents had gone out and shut the door of the room, Tobias got out of bed and said to Sarah, ‘Sister, get up, and let us pray and implore our Lord that he grant us mercy and safety.’ So she got up, and they began to pray and implore that they might be kept safe. Tobias began by saying,
‘Blessed are you, O God of our ancestors,
and blessed is your name in all generations forever.
Let the heavens and the whole creation bless you forever.
You made Adam, and for him you made his wife Eve as a helper and support.
From the two of them the human race has sprung.
You said, ‘It is not good that the man should be alone;
let us make a helper for him like himself.
I now am taking this kinswoman of mine,
not because of lust,
but with sincerity.
Grant that she and I may find mercy
and that we may grow old together.’” 
The Book of Tobit has other delightful stories of miraculous healings, but it definitely reads like a short novella, it really does not seem to depict an actual event.
There is no debating that the Book of Judith is merely a fanciful story, and a very gruesome story at that. The introduction includes a short history of the protagonist King Holofernes that is so absurd that there is no doubt that this likely does not depict an actual event.
King Holofernes wins many battles against the armies of the Israelites, so Judith announces to the leaders that she will go to the camp of Holofernes to see how God can answer her prayers and subdue Holofernes.
Quoting from the Book of Judith:
“Judith removed the sackcloth she had been wearing, took off her widow’s garments, bathed her body with water, and anointed herself with precious ointment. She combed her hair, put on a tiara, and dressed herself in the festive attire.” “She put sandals on her feet, and put on her anklets, bracelets, rings, earrings, and all her other jewelry. Thus she made herself very beautiful, to entice the eyes of all the men who might see her.”
We know the demands of this literary genre, how our heroine and widow Judith is somehow not supposed to lose her chastity, but somehow outsmart Holofernes nonetheless. She first offers false counsel on how he can win the battle, and they become acquainted over several days, because everyone knows you have to wait until after a few dates, and then we read:
After fours days, this happens: “Then Judith came in and lay down. Holofernes’ heart was ravished with her and his passion was aroused, for he had been waiting for an opportunity to seduce her from the day he first saw her. So Holofernes said to her, “Have a drink and be merry with us!” Judith said, “I will gladly drink, my lord, because today is the greatest day in my whole life.”
And our villain Holofernes drinks and drinks and drinks, and sleeps and sleeps and sleeps, then our heroine, Judith, who returns to the Israelite camp to pull his head from her bag to show it to all the brave soldiers of the camp.
The painter Gustav Klimt caused quite a stir with his interpretation of this story, when he implicitly implied that it was not merely the wine that caused our villain Holofernes to fall into such a deep sleep.
A special mention is the Book of Esther, a book many early rabbis argued should not be included in the canon because it never mentions or prays to God for assistance. What guaranteed its place in the Jewish canon was the Purim Festival inspired by Esther, a favorite holiday among Jewish children to the present day as we can see these 1960’s Wikipedia photos from Israel.
Esther was chosen to be one of many queens to the King of Persia in an ancient beauty contest, she hid her Jewish identity, as the story goes, so she could be of use to her people if necessary. And she condemned Haman who was plotting to persecute her Jewish compatriots.
The Greek translation of Esther adds prayers and other material that are absent from the Hebrew translation.
So, we come back to our original question, Should the books of the Apocrypha be included in the Bible?
If this channel we focused on arguing that Protestants are saved, but Catholics not so much, or that Catholics are saved, but Protestants not so much, then this is the question we would be eager to answer and polemically argue about.
But since this channel prefer to find similarities rather than differences in the various Judaeo-Christian traditions, we prefer to restate the question as: Can all Christians benefit from reading the Apocrypha?
The answer is yes, everyone can benefit from reading the books of the Apocrypha, and, IMHO, the differences between Catholics and Protestants are not that divergent, many Catholics view these books as last in the canon, and Protestants, if they wish to avoid needless polemics, can see these books as being almost in the canon.