A lot of evangelical Christians have an unrealistic and simplistic picture of the continuity of the Bible. For instance, sometimes you see the claim that it would have been impossible for the text of the Torah to have changed because there were just too many copies and the text was too spread out. But in reality there were several moments when the text was incredibly vulnerable to change. An interesting account can be seen in the Bible itself.
2Kgs.22[3] In the eighteenth year of King Josi'ah, the king sent Shaphan the son of Azali'ah, son of Meshul'lam, the secretary, to the house of the LORD, saying,[4] "Go up to Hilki'ah the high priest, that he may reckon the amount of the money which has been brought into the house of the LORD, which the keepers of the threshold have collected from the people;[5] and let it be given into the hand of the workmen who have the oversight of the house of the LORD; and let them give it to the workmen who are at the house of the LORD, repairing the house,[6] that is, to the carpenters, and to the builders, and to the masons, as well as for buying timber and quarried stone to repair the house.[7] But no accounting shall be asked from them for the money which is delivered into their hand, for they deal honestly."[8] And Hilki'ah the high priest said to Shaphan the secretary, "I have found the book of the law in the house of the LORD." And Hilki'ah gave the book to Shaphan, and he read it.
In other words, the Torah was found in the Temple (implying that it was lost before this point). And lest you want to argue that this was just some kind of redundant copy, consider the way the king and others seem to respond to the Torah as if it were new information.
[9] And Shaphan the secretary came to the king, and reported to the king, "Your servants have emptied out the money that was found in the house, and have delivered it into the hand of the workmen who have the oversight of the house of the LORD."[10] Then Shaphan the secretary told the king, "Hilki'ah the priest has given me a book." And Shaphan read it before the king.[11] And when the king heard the words of the book of the law, he rent his clothes.[12] And the king commanded Hilki'ah the priest, and Ahi'kam the son of Shaphan, and Achbor the son of Micai'ah, and Shaphan the secretary, and Asai'ah the king's servant, saying,[13] "Go, inquire of the LORD for me, and for the people, and for all Judah, concerning the words of this book that has been found; for great is the wrath of the LORD that is kindled against us, because our fathers have not obeyed the words of this book, to do according to all that is written concerning us."
In other words, at this time, the children of Israel were at a particularly low point in terms of knowing and obeying the law, so much so that when the king read the book of the law he was genuinely shocked about what it said.
[...]2Kgs.23[1]Then the king sent, and all the elders of Judah and Jerusalem were gathered to him.[2] And the king went up to the house of the LORD, and with him all the men of Judah and all the inhabitants of Jerusalem, and the priests and the prophets, all the people, both small and great; and he read in their hearing all the words of the book of the covenant which had been found in the house of the LORD.[3] And the king stood by the pillar and made a covenant before the LORD, to walk after the LORD and to keep his commandments and his testimonies and his statutes, with all his heart and all his soul, to perform the words of this covenant that were written in this book; and all the people joined in the covenant.
So things got so bad that the king felt a need for the people of Judah to rededicate themselves to following the Torah The next dozen or so verses then go into vivid detail about how deeply entrenched paganism had become in the land and what steps had to be taken to uproot it.
[4] And the king commanded Hilki'ah, the high priest, and the priests of the second order, and the keepers of the threshold, to bring out of the temple of the LORD all the vessels made for Ba'al, for Ashe'rah, and for all the host of heaven; he burned them outside Jerusalem in the fields of the Kidron, and carried their ashes to Bethel.[5] And he deposed the idolatrous priests whom the kings of Judah had ordained to burn incense in the high places at the cities of Judah and round about Jerusalem; those also who burned incense to Ba'al, to the sun, and the moon, and the constellations, and all the host of the heavens.[6] And he brought out the Ashe'rah from the house of the LORD, outside Jerusalem, to the brook Kidron, and burned it at the brook Kidron, and beat it to dust and cast the dust of it upon the graves of the common people.[7] And he broke down the houses of the male cult prostitutes which were in the house of the LORD, where the women wove hangings for the Ashe'rah.
So even in the Temple in Jerusalem there had been idol worship and cult prostitutes!
[8] And he brought all the priests out of the cities of Judah, and defiled the high places where the priests had burned incense, from Geba to Beer-sheba; and he broke down thehigh places of the gates that were at the entrance of the gate of Joshua the governor of the city, which were on one's left at the gate of the city.[9] However, the priests of the high places did not come up to the altar of the LORD in Jerusalem, but they ate unleavened bread among their brethren.[10] And he defiled To'pheth, which is in the valley of the sons of Hinnom, that no one might burn his son or his daughter as an offering to Molech.[11] And he removed the horses that the kings of Judah had dedicated to the sun, at the entrance to the house of the LORD, by the chamber of Nathan-melech the chamberlain, which was in the precincts; and he burned the chariots of the sun with fire.[12] And the altars on the roof of the upper chamber of Ahaz, which the kings of Judah had made, and the altars which Manas'seh had made in the two courts of the house of the LORD, he pulled down and broke in pieces, and cast the dust of them into the brook Kidron.[13] And the king defiled the high places that were east of Jerusalem, to the south of the mount of corruption, which Solomon the king of Israel had built for Ash'toreth the abomination of the Sido'nians, and for Chemosh the abomination of Moab, and for Milcom the abomination of the Ammonites.[14] And he broke in pieces the pillars, and cut down the Ashe'rim, and filled their places with the bones of men.[15] Moreover the altar at Bethel, the high place erected by Jerobo'am the son of Nebat, who made Israel to sin, that altar with the high place he pulled down and he broke in pieces its stones, crushing them to dust; also he burned the Ashe'rah.[16] And as Josi'ah turned, he saw the tombs there on the mount; and he sent and took the bones out of the tombs, and burned them upon the altar, and defiled it, according to the word of the LORD which the man of God proclaimed, who had predicted these things.[17] Then he said, "What is yonder monument that I see?" And the men of the city told him, "It is the tomb of the man of God who came from Judah and predicted these things which you have done against the altar at Bethel."[18] And he said, "Let him be; let no man move his bones." So they let his bones alone, with the bones of the prophet who came out of Sama'ria.[19] And all the shrines also of the high places that were in the cities of Sama'ria, which kings of Israel had made, provoking the LORD to anger, Josi'ah removed; he did to them according to all that he had done at Bethel.[20] And he slew all the priests of the high places who were there, upon the altars, and burned the bones of men upon them. Then he returned to Jerusalem.
Things had gotten so bad that people had even stopped keeping Passover.
[21] And the king commanded all the people, "Keep the passover to the LORD your God, as it is written in this book of the covenant."[22] For no such passover had been kept since the days of the judges who judged Israel, or during all the days of the kings of Israel or of the kings of Judah;[23] but in the eighteenth year of King Josi'ah this passover was kept to the LORD in Jerusalem.[24] Moreover Josi'ah put away the mediums and the wizards and the teraphim and the idols and all the abominations that were seen in the land of Judah and in Jerusalem, that he might establish the words of the law which were written in the book that Hilki'ah the priest found in the house of the LORD.[25] Before him there was no king like him, who turned to the LORD with all his heart and with all his soul and with all his might, according to all the law of Moses; nor did any like him arise after him.[26] Still the LORD did not turn from the fierceness of his great wrath, by which his anger was kindled against Judah, because of all the provocations with which Manas'seh had provoked him.[27] And the LORD said, "I will remove Judah also out of my sight, as I have removed Israel, and I will cast off this city which I have chosen, Jerusalem, and the house of which I said, My name shall be there."[28] Now the rest of the acts of Josi'ah, and all that he did, are they not written in the Book of the Chronicles of the Kings of Judah?
So what am I trying to say here? Maybe we can take the story at face value and the Torah was lost and then found intact. But if we are even just a little bit skeptical, this moment of Josiah's reforms presents a perfect opportunity for the text to have been redacted.
Allahu alim.