The Bible is a very old document. There are not many things like it. I should say there is not anything like it. Writing materials (papyrus, animal skins, clay, even stone) do not last forever. For ancient writings to have survived to the present, they had to be copied over and over. Copying can be the source of error. Then there is the matter of whether the original writers made it up or got it right. For these purported reasons, some don’t put any weight in the words of the Bible. But they do trust other witnesses. Should they?
The Bible has more than 5000 existing hand-written manuscripts or portions of manuscripts of the New Testament. Many of these dated within 200 years of the original. No other notable document of antiquity has anywhere near that. Because there are so many, exhaustive comparative study has been done to look for variations due to copying error or intentional redaction. Those things exist, but they are readily identified. The result is that we can be pretty darn sure what the originals said. The remaining questions about the originals are largely inconsequential. The two biggest are whether the ending of the Gospel of Mark is original (Mark 16:9-20)and whether the story of woman caught in adultery is original (John 7:53-8:11). The only doctrinal impact these passages might have is whether we should handle snakes in worship. I say no.
Was there a big lag time between Jesus’ life and the writing of the New Testament? Dating of the earliest manuscripts and non-biblical evidence for the existence of “Christians” would suggest that Christianity began within the lifetime of eyewitnesses. The lag to the earliest written recordings is no more than a decade or two, if that. Still, a decade is a long time for human memory, couldn’t the writers of the New Testament have remembered things they way the wanted to remember them?
At this point, the issue is less about the human transmission of data and more about whether you trust in the existence of God. The eyewitnesses certainly would remember whether Jesus did miracles and rose from the dead. I can trust them with big stuff like that. If Jesus did these things, don’t you think He would be able to transmit the truth through human writers even a few decades later?
If someone would theorize that this is all a first century collusion to create a new religion for some reason, what is the motive? The early writers risked and in many cases lost their lives for this. The early church didn’t make money, but rather lost economic opportunity. The Apostle Paul adopted a religion he was persecuting. Why? For this same reason, the Islamic myth that the writers of the New Testament corrupted the truth and that Mohammed’s revelation was God’s correction, lacks reason about human behavior and how God would react or proof that Mohammed isn’t the real deceiver.
The Old Testament, being older, has more opportunity to being impugned by doubters. But the Dead Sea Scrolls gave testimony to the care given in making copies, and Jesus himself gives the Old Testament credence by quoting it.
I think the real reason that some dismiss the story and words of Jesus is because they don’t like them or they are afraid. It is denial. Others use lame untested arguments to never even look at the Bible. This is a dangerous mistake. The Bible may be old, but its content is extremely relevant to the purpose of our lives and what happens after our death. To ignore it for the reasons stated above is foolish in the most profound way.
If you wish to tell yourself that Jesus never existed or that we have no idea what Jesus actually said, to be consistent you should doubt the existence of anything or anybody before the invention of the printing press. Even then, maybe it is all a fiction. It’s a ridiculous thought, but it is God, not evidence that must disabuse you of such reasoning.