Virtually all early Christians trace back their conversion heritage to the 12 themselves (i.e. being converted directly by them, or being converted by someone was converted by them, or by someone who was converted by someone who was converted by them etc.). This is relevant assuming that, like most ancients, Christian converts tended to take as teachers/authorities those who converted them (e.g. 1 Cor 1:12 “each one of you is saying,’“I am of Paul,’ and ‘I of Apollos,’ and ‘I of Cephas,’…”). And when those converts themselves won new converts, those new converts would likewise look back with respect to the original teacher/authority. So insofar as Christians all traced their heritage back to the apostles, all would look back at the apostles as being their authoritative teachers.
Paul repeatedly visited the Jerusalem church on the very assumption of his and the daughter churches that it was where the apostles lead and taught. When he went, and never learned otherwise; instead, his letters confirm it was the natural home of the apostles (even if they happened to away on missions etc.).
• He implies his confirmation of it in Acts 15:2, 22-30; 16:4.2
The book of Acts is a history of the early church, and it repeatedly assumes throughout that the apostles were the founders and leaders of the 1st church there in Jerusalem; they did not disappear.
• “[Christians] were continually devoting themselves to the apostles’ teaching…” (Acts 2:42)1
• They were the preachers at Pentecost [Acts 2:4-43]2
• Paul etc. went to them as leaders [Acts 15:2; 16:4]3
• Christians gave them their property etc. to manage [Acts 4:33; 35, 37; 5:2] 4 • The apostles as representatives were the ones interrogated, punished, sent to jail [Acts 5:18, 29, 40]5
• The apostles are who summon the congregation [Acts 6:2]6
• The apostles are who delegated management duties to Philip, Prochorus, Nicanor etc. [Acts 6:6]7
• The apostles are who Barnabas presents Paul to (as if they are in charge)[Acts 9:27]8
But no, Plausibly…
• The book of Acts does not relay testimony. (Forthcoming)
The earliest Christians (throughout the AD 30-70 mediterranean) honored the 12 apostles as the known authoriies of the church at large, heading up of all Christendom.
• E.g. The Gospels say the 12 were authorities.
• E.g. Later Christians say the 12 were authorities.
• E.g. Luke-Acts say the 12 were authorities.
• Sources justified their reliability via apostolic appeal.
• The apostles lead the Jerusalem church.
• The apostles converted the 1st Christians.
• Early Christians called them “pillars” etc.
• Lists of the names of the 12 were preserved.
• The 12 were the commissioned mouthpieces of Jesus.
• All desired to know and preserve the 12’s biography.
• There's no trace of real dispute over their authority.