The Old Testament was set by the Jews and Jesus and the apostles attestation. The New Testament was written from first hand account and the promise from Jesus that the Holy Spirit would “bring to their remembrance” the things that were taught and done. No one else had the promise.
>>And what those words mean?>>>p> 1 Corinthians 2:13 Which things also we speak, not in the words which man's wisdom teacheth, but which the Holy Ghost teacheth; comparing spiritual things with spiritual. 14 But the natural man receiveth not the things of the Spirit of God: for they are foolishness unto him: neither can he know them, because they are spiritually discerned. 15 But he that is spiritual judgeth all things, yet he himself is judged of no man. 16 For who hath known the mind of the Lord, that he may instruct him? but we have the mind of Christ.
There was no Jewish canon in the time of Jesus. The Sadducees rejected all but the Pentateuch. In the New Testament, we can point to quotes but this does not provide us with a complete list. Any mention of the Holy Spirit must take into account that the Holy Spirit speaks through men. Then we must ask who put together the New Testament canon? There were many more Christian texts than the 26,more “gospels” than the Four,and Revelation was not finally accepted until the i4th century. We Catholics knock on Luther for his skepticism about James, but even in 1500, the canon had not been set in concrete.