First we need to know what Scripture should be…
We can say that a book is inspired if God guided the authorship, so that it has no errors (it “cannot be broken,” Jn. 10:35), and if it has moral purity (“the word of the Lord is right,” Ps. 18:4), if it teaches us of God and his ways (Isa. 2:3), if it brings God’s power (Acts 19:20), and if it equips us for being righteous:
2 Timothy 3:16-17 All Scripture is God-breathed and is useful for teaching, rebuking, correcting and training in righteousness, so that the man of God may be thoroughly equipped for every good work.
Now with a definite concept of Scripture, then the problem becomes that of knowing which books fit this definition, for oftentimes discussions about the canon seem to be operating under the assumption that there are no firm criteria, it’s just what various church bodies decide what should be in the Bible, that determines what should be considered a canonical book.
But with a real standard, real decisions can be made, and we can understand the decisions that have chosen books to be in the canon.
Here is a quote regarding the process by which the four gospels became to be regarded as Scripture:
Hengel [in The Four Gospels and the One Gospel of Jesus Christ] shows that the titles on the canonical Gospels–“according to Matthew,” and so on–likely were already in place by at least 125. This would mean they circulated together, because the titles imply a distinction between, for example, Luke’s rendering and Mark’s. Indeed, the collection of four Gospels together may have been one of the first such collections to circulate in one codex or book.
Harry Gamble, in Books and Readers in the Early Church (Yale, 1995), shows at length that Christians in the second century quickly took to the codex (book form) rather than individual papyrus scrolls to more easily circulate multiple documents at once. He demonstrated that Paul’s letters also circulated in a collected form early in the second century. This is not just because these documents were popular. It is also because they were seen as representative apostolic texts that faithfully presented the earliest and most authentic evidence and interpretation of Christianity and its founder.
It is no accident that, in about 180, Irenaeus, bishop of Lyons, could already speak clearly and definitively about the fourfold Gospel, specifically citing those of Matthew, Mark, Luke, and John. He does so as he is opposing things he deems heretical. Thus, already in the second century, he has a strong sense of what amounts to orthodoxy when it comes to the story of Jesus.
Even before Irenaeus, from the middle of the second century, we have the witness of Justin Martyr, the great opponent of Marcion and his aberrations. In his Dialogue with Trypho (160), he calls the canonical Gospels “the reminiscences” of the apostles and says they were read and used in worship in his day. Nothing comparable is said about any other gospels, not even the Gospel of Thomas.
We can say without hesitation that various books that were to become part of the New Testament were already seen and used as authoritative and acceptable in the second century in various parts of the church, both Eastern and Western–and that their listing as authoritative in the early fourth century was without serious debate.
– Ben Witherington III (The Gospel Code: Novel Claims About Jesus, Mary Magdalene, and Da Vinci)
And here are some thoughts about the book of Tobit, which has been considered canonical by some branches of the church:
Tobit 5:13 Raphael answered, “I am Azariah, son of Hananiah the elder, one of your own kinsmen.”
I don’t think an angel would say something that’s just plain not true like that! Even though he does say he is really an angel later on…
Tobit 6:8 “As regards the fish’s heart and liver, if you burn them so that the smoke surrounds a man or a woman who is afflicted by a demon or evil spirit, the affliction will leave him completely, and no demons will ever return to him again.”
Nor do I think that is good counsel about dealing with demons! And does the Catholic church make that part of an exorcism?
Tobit 6:9 And as for the gall, if you rub it on the eyes of a man who has cataracts, blowing into his eyes right on the cataracts, his sight will be restored.
This sounds almost like a spell of sorts, it’s certainly not true medically, and it seems to be a general procedure that should always work.
Tobit 6:12-13 Since you are Sarah’s closest relative, you before all other men have the right to marry her. … Since you have the right to marry her… I know that Raguel cannot keep her from you or let her become engaged to another man; that would be a capital crime according to the decree in the Book of Moses, and he knows that it is your right, before all other men, to marry his daughter.
But there was no penalty at all in the law of Moses for keeping a woman from being married, or for marrying a woman to someone less closely related to her. So this is an error in describing the law, I think.
Tobit 6:15 So now I too am afraid of this demon. Because he loves her, he does not harm her…
I really don’t think demons love people! No they don’t…
Tobit 12:9 … for almsgiving saves one from death and expiates every sin.
And almsgiving does not expiate sin…
As another example, there seem to be historical errors in the book of Judith, Nebuchadnezzar is said to be the king of the Assyrians, but he was a Babylonian king, his throne was said to be in Nineveh, but it was in Babylon.
So I think these books are indeed correctly kept from the canon, and I will continue to hold to what I have been taught in this matter…