Kosonen:
So could it be that the writers of those non canonical books based their writings on those that already existed and just paraphrased what the inspired God’s prophets already had written?
To my knowledge the Christian Greek Scriptures almost exclusively quote from the canonical Hebrew scriptures. Maybe that was an important criteria in deciding what Hebrew scriptures should be included in the Bible?
First, the Bible was canonized by the Catholic Church under the authority of Rome.
The process was begun by the invention of the canon by Marcion of Sinope, a bishop who was trying to introduce Gnostic thought into Christianity, and went to the pope in Rome with his "new invention" of a "canon" of Christian writings that supported his Gnostic ideas in the 2nd century (though he was not a true Gnostic himself). It ended in the 4th century, exactly on Easter Sunday of 367 CE, when a bishop by the name of Athanasius authorized the New Testament canon developed by Eusebius which included the 27 books we hold today.
By default, the Church was acknowledging the "Old Testament" of the Alexandrine Septuagint, which included the so-called "Apocrypha." In the 1500s, during the Council of Trent, the Church defined these books as "Deuterocanonical," and listed each one of them, including the Wisdom of Solomon and Sirach. Interestingly, the King James Bible would also include a translation of each and every one of these, which to date are still included in many copies.
As to whether the writers of these books "copied" from others...
In the case of the Wisdom of Solomon, no one in Israel was expecting the Messiah to be betrayed by his own people, let alone the religious leaders. This prophecy is obviously about the leaders in Israel, most of which are religious, talking about murdering the Messiah by torture. The idea of this was even alien to the apostle Peter, remember?--Matthew 16:21-23.
Even when Jesus actually was betrayed, it was so unimaginable and confusing that his actual followers were scattered and hid. Some lost their faith. Only Mary, Mary Magdelene, and John the Apostle reportedly stayed with Jesus until the end--perhaps a few other of the women. Everyone else abandoned and fled who they believed was obviously a failed Messiah.
The section in the Wisdom of Solomon when read in context does not look like a prophecy nor does it even say it is about the Messiah, like most other prophecies in the Hebrew Scriptures. It is hidden. In fact, when you are reading the book, it is at the very beginning, talking about how the wicked reject righteousness in general and how they mistreat the poor and are unkind. It doesn't say outright that the writer is speaking about the Messiah.--See Wisdom of Solomon chapters 1 & 2.
The Church since the time of the Apostles has understood that this text is about the Messiah, since the Church Fathers who through Tradition claim it is one of the texts Jesus explained to them after his Resurrection.--Luke 24:44-46.
Jehovah's Witnesses do not study or read the Church Fathers--which is a very large collection of works. They just post a few tidbits of phrases here and there in their publications, and they tend to avoid any texts that are contrary to their beliefs. Catholics and most Protestants read and study these texts--Catholics and Orthodox Christians tend to do this daily along with the Bible in order to know the foundations of the Faith as these are the building blocks of where their faith and the teachings of Jesus come from.
As for the text in Sirach, it outright claims in the text that references to various other Scripture texts is taking place. The writer is obviously familiar with the Scriptures because he is talking about all the famous prophets in this section, and here he is talking about Elijah in particular.
But the point I was making is that in the gospel accounts the apostles do not claim that one prophet or scribe claims that Elijah comes first. They claim that plural scribes or prophets do this.
In other words, in Jesus time, the apostles and Jesus Christ himself acknowledged that multiple writers foretold the coming of Elijah, who would be John the Baptist.
They ask: "Why do the scribes say Elijah must come first?" and not "Why does Malachi say Elijah must come first?"
These "scribes" that the apostles and Jesus acknowledge as foretelling the coming of John the Baptist must not only include Malachi but also Sirach, because the Church Fathers and the early Church included that book in the Old Testament--and they teach this since antiquity. This is one of the reasons the book was left in the collection of the Old Testament.
In fact, it would not be until 1804 CE--almost 2000 years after Christ--when some Protestants in Britian would consider dropping the Apocrypha from their printings of the Bible. Up to that point, even Protestants always included the Apocrypha in their Bibles.--See the "Apocrypha Controversy" of the 1820s.
The criteria for including which Scriptures to include in the Old Testament was simply what was found in the Alexandrine Septuagint. This was the text used by the Apostolic college and the Church Fathers. Eventually this was the basis for the translation of the Latin Vulgate. Thus, this became the official canon of the Old Testament for Christians.
To this day, technically speaking, the Jews do not have a closed "canon." What they did was standardize and preserve the Hebrew text for fear it would be lost since Jews stopped talking in Biblical/litugical Hebrew before the 1st century CE (and there was yet no Modern/Israeli Hebrew to take its place to help preserve it). Beginning in the 8th century they had the family of the Masoretes, great scribes, begin collecting the best extant Hebrew manuscripts, compare them and then develop a standardized Hebrew text. They completed it in the 10th century. It is what we call today the Masoretic text.
It does not have, for example, the works of the Wisdom of Solomon or Sirach, for one reason since there were no Hebrew texts of these works at that time.
In the mid-20th century, the Dead Sea Scrolls were discovered. We found every book of the Bible, including the Apocrypha, except for Esther, among them, in Hebrew. Some of the most startling finds have been Isaiah and Tobit--Tobit being a so-called book of the Apocrypha.
One of the best new translations of Tobit based on the findings of the Dead Sea Scrolls is now available in the official Catholic Bible for the United States, the NABRE. It can be found online.
So to answer you question, no. These books were not making these things up by copying from other books of the "canonized" Bible (there was no "canon" yet, so to speak).
You obviously have little knowledge of the Scriptures and Biblical history.
Why are you offering us "encouragement" if you don't know these things or studied canonization history or familiar with the Church Fathers or the library of what books were in the ancient Christians' canon?