Yet Jesus said, study the scriptures...you do err, not knowing the scriptures... and quoted OT scripture frequently...and Paul taught in the synagogue daily,from the scriptures that Jesus is the Christ... and the Bereans who heard Paul preach are called nobel for searching the scriptures to see if it was so.
They had the OT scriptures
And when the NT was being written, it was written that all scripture is for doctrine, correction of wrong doctrine, and for instruction in righteousness.
None of the apostles appealed to oral tradition - but Jesus did criticize the Pharisees for their tradition.
Mar 7:9 And he said unto them, Full well ye reject the commandment of God, that ye may keep your own tradition.
BTW the Jerusalem church was the first Christian church, and it was the preeminent church for 70 years after Jesus ascended to heaven, until the Romans destroyed it in 70 AD.