Canonized or not, the oldest scrolls and documents containing the holy scriptures are nearly if not identical to the Holy scriptures we have today. Translation accuracy can be verified with Hebrew and Greek lexicons/concordances. I study scripture this way. The Word Of God is living and active and sharper than any two edged sword. Able to divide between soul and spirit, bone and marrow. It is the Treasure of the ages.
God loves us so much, and paid such a huge price to secure our redemption - He certainly can secure and keep His message, His Map, His Word Of Love and Truth from being perverted by the evil one who is bent on our destruction and who is delusional that he can overthrow The Ancient Of Days. The Great I Am, The Mighty God, The Everlasting Father, Holy One.
For whosoever shall call upon the name of the Lord shall be saved.