The 66 books of Scripture composing the canon of Scripture were inspired by God the Holy Spirit in the authors, all with the spiritual gifts to provide all mankind with His Word.
>>What verse in scripture says there are 66 books and not 5 books?
What is your authority for saying there aren’t 72 books or 80 for that matter?
What external criterion tells you that a book is scriptural?
Should the Gospel of John be thrown out considering it contradicts the Synoptics in several places? Not to mention the Gospel of Mark contradicts Luke in its telling of the parable of the paralytic?
Mark 2:4 says:
They couldn’t bring him to Jesus because of the crowd, so they dug a hole through the roof above his head. Then they lowered the man on his mat, right down in front of Jesus.
But Luke 5:19 says:
And not finding by what way they might bring him in because of the multitude, they went up to the housetop, and let him down through the tiles with his couch into the midst before Jesus.
Sola Scriptura undermines the Bible more than it defends it.
God Himself provides us His Word.
He gave us the Apostles, who with their spiritual gift from God the Holy Spirit, glorifying the Son, and given the gift as the Father had planned, provided us those books.
Upon the completion of the canon in 96AD, those gifts ceased.
A believer cannot know the Word of God outside of the doctrine of faith in his spirit and soul. Doctrine (faith) comes by hearing and hearing by the Word of God.
We know from the admonition in Revelation of the completion of the Canon. John was the Last Apostle.
We know from Timothy of the adequacy and sufficiency of the Word for every good work.
2Ti 3:16-17
(16) All scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness:
(17) That the man of God may be perfect, throughly furnished unto all good works.
We know His work in us from the Holy Spirit teaches us the truth.
1Jn 2:25-27
(25) And this is the promise that he hath promised us, even eternal life.
(26) These things have I written unto you concerning them that seduce you.
(27) But the anointing which ye have received of him abideth in you, and ye need not that any man teach you: but as the same anointing teacheth you of all things, and is truth, and is no lie, and even as it hath taught you, ye shall abide in him.
We also know the doctrine of the Hypostatic Union, by which our Lord Christ Jesus provided us the example of the Christian way of thinking in this Church Age. Remaining in fellowship with God, through faith in Christ, never ceasing in prayer to the Father, and allowing God the Holy Spirit to perform His work in us to glorify the head, our Lord and Savior Christ Jesus.
The verses quoted further demonstrate the verifiability of both in the historical record. All of human history is His Story.
Sola Scriptura neither undermines, nor defends the Bible, but instead glorifies His Word and encourages the work of God the Holy Spirit in every believer.