I agree - but they had no New Testament for decades. Thus, how, if someone implies you can’t manage a religious service without a Bible, then how did the Apostles do it without a Bible? All you’re telling us is that they relied on the TRADITION passed down to them by Christ. So much for sola scriptura. Thanks for the assist!
Have you forgotten that the Apostles used the Old Testament scriptures when they taught the truth of Jesus being the Messiah? And, curiously enough, as did Jesus when he taught? Are those Apostles still alive and teaching today or does their teaching (given to them by the Holy Spirit) still reside with us in the form of the sacred Scriptures? The "traditions" that made up the rule of the Christian faith are now enscripturated for us all in the Bible. That is why sola Scriptura is every bit a viable and necessary doctrine today.