When Paul writes (Ephesians 5:14): “Thus God speaks through the scriptures: ‘Awake, you who sleep, arise from the dead, and Christ will give you light,’” which scriptures is he referring to?
The King James Version simply has: “Wherefore he saith, Awake thou that sleepest, and arise from the dead, and Christ shall give thee light.” And so does the Greek text. (Most “modern language” translations are interpretive to the point of dishonesty.)
Saint Paul quotes words of Jesus not found in the Gospels and Saint Jude cites a prophecy of Enoch. So we can be sure that the Christians in the early days had access to writings now lost through persecutions, wars and the deliberate destruction by those who thought their own version of Christianity was the only right one.
All the Christian world read the more than three hundred books of Origen until a Church council declared them heretical and they were destroyed. Today we have only a few of them still existing.
When he writes: “All scripture is inspired by God and is useful for teaching the faith and correcting error, for re-setting the direction of a man’s life and training him in good living. The scriptures are the comprehensive equipment of the man of God and fit him fully for all branches of his work,” is he referring to ALL scriptures or just what mainstream Christianity would consider the “Old Testament”?
First of all, the real text says:
“All scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness: that the man of God may be perfect, throughly furnished unto all good works” (II Timothy 3:16-17).
See from this how much that you quoted is just somebody’s ideas masquerading as scripture. I urge you to get a trustworthy translation of the Bible: both the King James Version and the New King James Version are good.
Since there was no such thing as the Bible until the fourth century, what Saint Paul meant by “scripture” is anyone’s guess.
“Other” scriptures
We do know that the Books of Hermas and the Epistles of Saint Ignatius of Antioch as well as many Gospels other than the four were freely read in the churches and at home by Christians.
There is a very interesting book called The Lost Books of the Bible and the Forgotten Books of Eden. A very scholarly and honest collection is The Apocryphal New Testament by M. R. James. You might find both interesting.
This all underlines the fact that you cannot get your religion from books alone. But the best certainly is the Bhagavad Gita which says: “Therefore be a yogi” (Bhagavad Gita 6:46).