The gospels of Matthew and Mark each contain a complete list of Jesus’s twelve disciples, or apostles. The two lists have all the same names. One of the disciples is named Thaddaeus, and Judas Iscariot is the only Judas on the list:
- Simon Peter
- Andrew
- James son of Zebedee
- John
- Philip
- Bartholomew
- Thomas
- Matthew
- James son of Alphaeus
- Thaddaeus
- Simon the Zealot
- Judas Iscariot
The gospel of Luke also has a list of the twelve disciples, but this one has two people named Judas, and no one named Thaddaeus:
- Simon Peter
- Andrew
- James
- John
- Philip
- Bartholomew
- Matthew
- Thomas
- James son of Alphaeus
- Simon the Zealot
- Judas son of James
- Judas Iscariot
The book of Acts lists all the same apostles as Luke except Judas Iscariot, since he was dead by that time. The gospel of John doesn’t have a list of all twelve disciples, but it agrees with Luke and Acts that there was a Judas other than Judas Iscariot among them.
But John also says one of the disciples was named Nathanael. He’s not mentioned in any other book.
There are more people who are called apostles in the Bible. And it says some people claim to be apostles but are not, so it’s not at all clear which ones are the twelve who will have their names written on the foundations of the New Jerusalem. Matthias was chosen to replace Judas Iscariot as the twelfth apostle, because Judas had died. So does Matthias get his name on a foundation and not Judas? If so, do none of the other original Twelve get their names on a foundation either, since they all died too?
Then there’s the self-proclaimed “apostle” Paul, and his companion Barnabas, who is also called an apostle at one point. So are Andronicus and Junia. The book of Hebrews even says Jesus was an apostle.
How can Jesus be one of the apostles? What is an apostle, anyway? The broad, literal meaning of the word is a messenger or ambassador. So I guess it makes sense to call all those people apostles in that sense. But that doesn’t explain why there are more than twelve people who the Bible says were part of the Twelve.