What is 1 Corinthians 15:5, mean when it says Jesus appeared to Peter, and
then to the Twelve? Are the Twelve, the 12 apostles during Jesus’
ministry? Because Judas was dead when Jesus appeared to everyone who saw.
And Matthew 28 says he appeared to the Eleven. Do you know what the
scripture is referring to?

The only reasonable assumption is that in 1 Corinthians 15:5 he is
referring to the apostles. The apostles were often referred to as the
Twelve, both in the New Testament (Acts 6:2, John 6:67,70), and in early
Christian writings. It is true that for a short period of time, there were
only eleven living apostles. This, of course, was the time between the
suicide of Judas Iscariot and the appointment of Matthias, recorded in
Acts 1:23-26. It just so happens that all of the resurrection appearances
occurred during this time. Nevertheless, at the time 1 Corinthians was
written, “the Twelve” was a normative phrase which stood for the apostles,
so one should not be surprised that Paul uses this phrase in 1 Corinthians
15:5, despite the fact that one could argue that technically Paul is wrong
in saying twelve. Paul would have lost the train of thought in his
conversation with his hearers if he had gone into the detail of the fact
that there were actually only eleven apostles at the time of the
resurrection appearances.

One reason I believe this is the correct conclusion is that I have never
heard of nor can I think of any other reasonable thing which the Twelve
can be referring to in 1 Corinthians 15. In this case, the simple answer
is almost certainly the correct one.

John Oakes, PhD