After Pentecost the apostles and disciples spread what Jesus had taught them among people living around the Mediterranean. Paul's letter to the Thessalonians is the earliest piece in the New Testament. Scholars date it around the year A.D. 50. We don't know of any written account of Jesus' life and teaching until Mark's Gospel, which was written around the year a.d.70. The last Gospel, John's, probably wasn't written in its final form until about a.d.90. If Jesus died around the year 30 that means that the transmission of His revelation dependent on word of mouth to a great extent in the years after Jesus' death and resurrection. Catholics believe that the Holy Spirit was with the Church during those times in both the spoken and written records of Christ's life and teaching.
We Catholics respect both the sacred Tradition that is written and that which was passed on by word of mouth. John said at the end of his Gospel, "There are many other things that Jesus did, but if these were to be described individually, I don't think the whole world would contain the books that would be written" (John 21:25). St. Paul speaks of the oral and written Tradition when he writes, "Therefore, brothers, stand firm and hold fast to the traditions that you were taught, either by an oral statement or by a letter of ours" (2 Thess. 2:15).
How do we assess those oral traditions that aren't explicitly found in the Scriptures?
We look to the beliefs and teachings in the early Church. Just as the Church needed to discern which of the many writings about Jesus were to be included in the final edition or canon of the Bible, so the church continues to clarify other beliefs of divine revelation. Catholics believe, for example in Mary's lifelong virginity, her immaculate conception, and her assumption not because they are explicitly found in the written Scriptures, but because they were facts of revelation known through a verified Tradition not found in the written tradition of our Scripture. These sacred traditions never contradict the written word.
Have a comment or question to share with Fr. Mike? Click here or email Fr. Mike at email@example.com .