Summary: The New Testament writings (Scriptures) come to us as a direct result of the prophecy given in portions of John 14-17.
Jesus appeals to the authority of Scripture in John 5, saying that it is they which testified of Him.
39 You search the Scriptures, for in them you think you have eternal life; and these are they which testify of Me 45 Do not think that I shall accuse you to the Father; there is one who accuses you--Moses, in whom you trust. 46 For if you believed Moses, you would believe Me; for he wrote about Me.
At His death, He quotes and lives out the Scripture found in Psalm 22:1,
My God, my God, why have You forsaken Me?
After He is raised from the dead, He rebukes two disciples because of their unbelief. Unbelief in Him? Yes, but only indirectly. They are rebuked because of their unbelief of the words of the prophets in the Scriptures! Then Jesus gave them the Bible lesson of their lives:
25 Then He said to them, "O foolish ones, and slow of heart to believe in all that the prophets have spoken! 26 Ought not the Christ to have suffered these things and to enter into His glory?" 27 And beginning at Moses and all the Prophets, He expounded to them in all the Scriptures the things concerning Himself.
One might say, of course Jesus endorsed the Jewish law. He was a Jew speaking to Jews. They all believed that the Word of God was perfect, unable to be broken, sufficient, in fact all the things we believe about the Bible today. But how could Jesus have endorsed and authorized the writing of the New Testament, when it was still in the future?
In order for there to be a “New Testament” in book form, there would have to be new revelations. Would these messages come from a new set of prophets? Nearly so. But in this case, the “prophets” were called “apostles.” They would be the ones, through the ministry of the Holy Spirit, to receive a series of messages that would be passed on to the end of time. Jesus’ provision for this task is outlined so very clearly in the final address of Jesus to the 12, now the 11, in John 14-16, and the great “Lord’s Prayer” of John 17. Look carefully at the following promises and instructions:
25 "These things I have spoken to you while being present with you. 26 But the Helper, the Holy Spirit, whom the Father will send in My name, He will teach you all things, and bring to your remembrance all things that I said to you.
15 No longer do I call you servants, for a servant does not know what his master is doing; but I have called you friends, for all things that I heard from My Father I have made known to you 26 "But when the Helper comes, whom I shall send to you from the Father, the Spirit of truth who proceeds from the Father, He will testify of Me. 27 And you also will bear witness, because you have been with Me from the beginning.
12 I still have many things to say to you, but you cannot bear them now. 13 However, when He, the Spirit of truth, has come, He will guide you into all truth; for He will not speak on His own authority, but whatever He hears He will speak; and He will tell you things to come. 14 He will glorify Me, for He will take of what is Mine and declare it to you. 15 All things that the Father has are Mine. Therefore I said that He will take of Mine and declare it to you.