What are the biggest changes or differences in old Bible manuscripts?

Most manuscript differences are minor—spelling, word order, an accidentally repeated line. Scholars who study this closely have identified a small number of more meaningful variants, and it's worth knowing what they actually are, since they're often described dramatically without much detail.

One well-known example is 1 Timothy 3:16. Some later manuscripts read "God was manifested in the flesh," while the earliest manuscripts read simply "he was manifested in the flesh." Most modern translations follow the earlier reading. Either way, the doctrine that Jesus is God doesn't depend on this one verse—it's supported by many other passages.

Another is the ending of the Lord's Prayer. The familiar line "for yours is the kingdom and the power and the glory forever, amen" doesn't appear in the earliest manuscripts of Matthew, and was likely added later, possibly from early church liturgical use.

A third is the well-loved story of the woman caught in adultery, found in John 7:53–8:11. It's missing from the earliest Greek manuscripts, and most scholars think it was added later—though many also think it may preserve a genuine, separately remembered story about Jesus, even if it wasn't originally part of John's Gospel.