How can one be sure that the Scripture, revealed and inspired by God and recognized as canonical by the early church, has been handed down to this day without any loss of material?

Because God preserved it.

Before the written Word of God was ever attacked, Satan persistently tried to undermine the spoken Word of God. One of his attack schemes is to first raise doubt by questioning God’s Word, then to outright deny its truth. In the beginning, Satan questioned God’s Word when he asked Eve, “Did God really say you must not eat the fruit from any of the trees in the garden?” (Genesis 3:1). Then he denied God's Word when he asserted, “You won’t die!” (vv. 4). This scheme has been repeated over and over again throughout history.

Another satanic scheme is to twist the meaning of Scripture. Satan attempted to distort the Scripture in his wilderness encounter with Christ (Matthew 4:6–7). He quoted Psalm 91:11–12 out of context, suggesting that Jesus should put God to the test by throwing himself down from the temple pinnacle since God promised to protect Him. However, Jesus rightly pointed out that Scripture also says, “You must not test the Lord your God” (Deuteronomy 6:16), thereby showing that Satan was twisting the meaning of the Psalm.

When God’s Word was eventually written into the form we have today, Satan continued using this strategy to create doubt, denial, and deception.

At other times, Satan’s attacks have not been subtle. Through King Jehoiakim, he attempted to literally destroy the Word. “Each time Jehudi finished reading three or four columns, the king took a knife and cut off that section of the scroll. He then threw it into the fire, section by section, until the whole scroll was burned up” (Jeremiah 36:23).

Throughout history, there have been many efforts to destroy the Bible through overt and physical attacks. For example, in 175 BC, the king of Syria, Antiochus Epiphanes, ordered the Jews, on pain of death, to destroy their Scriptures and worship the Greek gods. But Judas Maccabeus saved the books and led a revolt that won independence for the Jewish nation.

In AD 303, the Roman emperor Diocletian ordered that Christianity be outlawed, its leaders killed, and their Bibles burned. In God’s providence, the next emperor, Constantine (AD 313), legalized Christianity and even paid for 50 new handwritten copies of the Bible.

Intellectual attacks on Scripture have persisted throughout history as well. Philosophers such as Celsus (AD 178) and Porphyry (AD 232–303), along with the Roman emperor Julian (AD 361), a nephew of Constantine, renounced Christianity, were openly hostile to the Bible, and wrote against it.

Scripture even survived the opposition of its so-called friends. On numerous occasions in centuries past, church authorities burned the Bible under the guise that the translation was vulgar. They stated that it would do more harm than good. Thousands of copies were destroyed.

Modern rationalism also attacked Scripture. Rationalists argued that biblical events must be judged in the light of human reason and experience, questioning the reality of Jesus’ miracles and denying Christ’s deity. Figures like Voltaire, Thomas Paine, and Robert Ingersoll passionately attacked the Bible. These critics have since passed on, but the Bible continues to endure.

God intended His Word to abide forever. He anticipated humanity’s and Satan’s malice towards Scripture with divine promises to preserve it. The continued existence of Scripture is guaranteed in Isaiah 40:8, “The grass withers and the flowers fade, but the word of our God stands forever.” Jesus also affirmed in Matthew 24:35, “Heaven and earth will disappear, but my words will never disappear.”

The fact that God has preserved His Word also means that no inspired Scripture has been lost in the past and is still awaiting rediscovery. The actual content of Scripture will be perpetuated both in heaven—“Your eternal word, O Lord, stands firm in heaven” (Psalm 119:89)—and on earth—“‘And this is my covenant with them,’ says the Lord. ‘My Spirit will not leave them, and neither will these words I have given you’” (Isaiah 59:21).

The indestructability of the Bible also means the purposes of God, as written in Scripture, will never be thwarted, even in the smallest detail. Jesus affirmed this in Matthew 5:18, “I tell you the truth, until heaven and earth disappear, not even the smallest detail of God’s law will disappear until its purpose is achieved.” And through Isaiah the Lord said, “It is the same with my word. I send it out, and it always produces fruit. It will accomplish all I want it to, and it will prosper everywhere I send it” (Isaiah 55:11).

God has given us very simple instructions for the preserving of His Words. He tells us repeatedly not to add or take away from it. This is preservation in all its simplicity. Deuteronomy 4:2 is the first text warning us not to add or take away from the Word of God. Notice how preservation and obedience go together: “Do not add to or subtract from these commands I am giving you. Just obey the commands of the Lord your God that I am giving you.” Deuteronomy 12:32 reiterates this truth saying, “So be careful to obey all the commands I give you. You must not add anything to them or subtract anything from them.”

Revelation 22:18–19 are possibly the best-known verses on the preservation of the Bible: 

And I solemnly declare to everyone who hears the words of prophecy written in this book: If anyone adds anything to what is written here, God will add to that person the plagues described in this book. And if anyone removes any of the words from this book of prophecy, God will remove that person’s share in the tree of life and in the holy city that are described in this book.

Not only has the Bible survived its attackers and critics, but it’s the best-selling book of all time. Each year the Bible outsells all other books. Its critics have railed and ranted, only to pass away and be forgotten with time, yet the Word of the Lord has lived on. It will continue to be the world’s best-seller. Despite the attacks on the written Word of God, the abundance of copies of Scripture available today is powerful proof of God’s preservation. As 1 Peter 1:24–25 says, “The grass withers and the flower fades. But the word of the Lord remains forever.”

The efforts to destroy the Bible rage on, but Scripture has and will continue to outlast its enemies. Even if all people turn away from the Word of God, it will remain indestructible. God has said that Scripture will endure until heaven and earth pass away and we meet on the Day of Judgment. For now, we must read it with understanding, obey its every commandment, live by it, die by it, and thereby share the great promises contained within it.