How do we know the Bible hasn't been changed over time?

We can't check the Bible against a lost, perfect original—no ancient document has one that survived. What we do have is an enormous number of copies, which is actually how experts check accuracy.

A method called textual criticism compares thousands of manuscripts, copied across different centuries and regions, to spot where a scribe made a mistake or change, and reconstruct the earliest recoverable wording. Because copies come from so many independent lines, an error introduced in one place is usually caught by comparison with others that don't have it.

Most differences that turn up are tiny: spelling, word order, obvious slips. A much smaller number are more substantial, and reputable Bibles are upfront about those, usually with a footnote explaining what the manuscripts show, rather than hiding it.

No core Christian teaching depends on one of these disputed passages standing alone. The overall picture that emerges from comparing so much evidence is a text transmitted with real, checkable accuracy—not a perfect process, but a remarkably well-documented one.