Q. If popes and bishops are necessary then why were there none in the early church?
A. In the early Church there were all three ordained offices of the Catholic Church that we have today (Deacons, Priests, Bishops). They were called by different names but the offices were in existence and are designated in Acts 6:5 and Acts 15 at the first Church Council and elsewhere in the New Testament.
Q. Then why have I never seen that in Acts 15 before? I have read it many times.
A. You surely saw it but just missed the significance of the information you were reading.
First, we have Peter at the council who stood up and settled the dispute, made the POPE or Vicar of Christ in Matthew 16:17-19.
Then, also present at the first Church Council were the apostles who became the first BISHOPS ( Gr. Episkopos) in the Church. There are many other New Testament passages that mention the office of bishop or overseer.
Next we see PRIESTS, called elders in the New Testament because this is the strict English translation of the Greek presbuteros. However, our English word Priest is etymologically derived from the Greek word presbuteros.
And finally we have DEACONS. Stephen and others in Acts 6 and qualifications of deacons in I Timothy 3:8-12. There are many other NT passages also that talk about deacons.