The human writers of the Holy Scripture were Catholic because everything they wrote the Catholic Church teaches today, and always has. They were demonstrably not Protestant because Protestantism believes that salvation is through faith alone, and the scripture says the exact opposite.
“They were demonstrably not Protestant because Protestantism believes that salvation is through faith alone, and the scripture says the exact opposite.”
The problem with that statement is when Paul is writing to Jewish believers who taught that salvation is through faith plus works, he corrected them with the following,
Rom. 9:30-32, “What shall we say then? That the Gentiles, which followed not after righteousness, have attained to righteousness, even the righteousness which is of faith.But Israel, which followed after the law of righteousness, hath not attained to the law of righteousness. Wherefore? Because they sought it not by faith, but as it were by the works of the law.”
Rom. 10:2-4, “For I bear them record that they have a zeal of God, but not according to knowledge. For they being ignorant of God’s righteousness, and going about to establish their own righteousness, have not submitted themselves unto the righteousness of God. For Christ is the end of the law for righteousness to every one that believeth.”
Rom. 10:8-13 “The word is nigh thee, even in thy mouth, and in thy heart: that is, the word of faith, which we preach; That if thou shalt confess with thy mouth the Lord Jesus, and shalt believe in thine heart that God hath raised him from the dead, thou shalt be saved. For with the heart man believeth unto righteousness; and with the mouth confession is made unto salvation. For the scripture saith, Whosoever believeth on him shall not be ashamed. For there is no difference between the Jew and the Greek: for the same Lord over all is rich unto all that call upon him. For whosoever shall call upon the name of the Lord shall be saved.”