Acts 1 shows that their office survives their deaths and that others were chosen to fill it. Indeed, the letter from the Council of Jerusalem in Acts 15 was not by the apostles alone but by "the apostles and presbyters." The apostles were already appointing others to share in their authority for the governance of the church.
“Acts 1 shows that their office survives their deaths and that others were chosen to fill it.
There you go! You have God’s template for choosing a replacement Apostle!
He must have been with Christ and the other Apostles from the beginning, must have two such candidates nominated, and you must cast lots to determine the new Apostle.
Unfortunately, candidates meeting those qualifications are all gone to glory. This is why the Epistles call the Apostles the foundation stones.
“Indeed, the letter from the Council of Jerusalem in Acts 15 was not by the apostles alone but by “the apostles and presbyters.” The apostles were already appointing others to share in their authority for the governance of the church.”
Elders are a Church office. They were appointed in each church. We still have elders today.
Best.