One.
The Holy Ghost.
(I’m of course being pedantic. I’ve actually counted the number before by compiling a list of both traditional persons said to be authors and modern scholarly ideas)
My finding was about ~90 Prophets/Sacred Authors wrote the Old Testament, and about ~12 Apostles wrote the New Testament, for a total of about ~112 original Sacred Authors.
The 12 New Testament Sacred Authors:
- St. Matthew the Apostle and Evangelist
- St. Mark the Apostle and Evangelist
- St. Luke the Apostle and Evangelist
- St. John the Apostle, Evangelist, and Theologian
- St. James the Apostle
- St. Peter the Apostle
- St. Paul the Apostle
- St. Jude the Apostle
- St. Tertius the Apostle
- St. Sosthenes the Apostle
- St. Timothy the Apostle
- St. Silvanus the Apostle
And for the Old Testament:
Possibly Adam, Noah, Shem, Abraham, Isaac, Jacob and Joseph could have left some written records
Moses
Aaron
Joshua
Yahwist authors (likely Davids court Prophet-scribes)
Elohist authors (likely Prophet-Scribes in the Israelite Kingdom)
Deuteronomist authors (likely various Prophets of the various prophetic schools/guilds)
Priestly authors (men like Ezekiel)
Samuel
Nathan
Gad
Abiathar
Job
David
Solomon
The Chroniclers (probably Prophet-Scribes in the courts of Hezekiah or post exilic Sage-Prophets)
Ezra
Nehemiah
Disciples of Ezra-Nehemiah
Judith
Eliakim
Tobit
Mordechai
Esther
Men of the Great Sanhedrin
Jason of Cyrene
Judas Maccabee
Asaph
Sons of Korah
Ethan the Ezrahite
Heman the Ezrahite (these two are Psalmists, probably of the disciples of Ezra I mentioned previously)
Qoheleth
Prophet-scribes of Hezekiah
Jesus ben Sirach and his grandson
Isaiah and possibly two or three of his disciples
Jeremiah
Baruch
Daniel
Hosea
Joel
Amos
Obadiah
Micah
Nahum
Habbakuk
Zephaniah
Haggai
Zechariah and possibly one or two of his disciples
Malachi
That’s about ~60+ authors right there.