One thing that’s notable for the Gospels is that the names of the Twelve apostles are not consistent between the various Gospels.
Here’s a list of names and their occurrences in the four canonical gospels:
5 are totally consistent (meaning they’re named all four Gospels)
Andrew (Peter’s brother in Matthew and Mark)
2 are probably consistent (meaning they’re named almost the same in all four Gospels)
James the son of Zebedee (Matthew, Mark); James (Luke)
John, the brother of James (Matthew, Mark); John (Luke)
“The sons of Zebedee” (John)
3 are in all three Synoptic Gospels (Matthew, Mark, Luke), but not John
Matthew (the tax collector in Matthew)
James the son of Alphaeus
Simon the Zealot
1 is in only Matthew and Mark
1 is only in Luke and John
Judas the son of James (in Luke)
Judas (not Iscariot) (in John)
1 is only in John
Lastly, the Gospel of John only names 8 apostles, though it refers to “the twelve” in John 6.
There is two more bits of interesting information from the Gospel of John. Namely, there are four people Jesus is said to love in it. “The disciple Jesus loved” is mentioned but not named. And Jesus is said to love the family of Bethany in John 11: Lazarus, Martha, and Mary. They are the only named individuals Jesus is said to have loved in that Gospel.
Is there a good explanation for the seeming inconsistency in the gospel lists of the apostles? John is certainly a more theologically-woven text, and its chronology doesn’t match that of the Synoptics, so it’s possible to read it as something other than literal history. However, there’s still not total consistency between Luke and the other Synoptics. Wikipedia notes that traditionally, Thaddeus and Judas are traditionally thought to have been the same person, “modern scholars” (again, according to Wikipedia) don’t agree.