I don't see where we get "new things" in any of these verses.
26âBut 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 that I said to you. John 14:26 NASB
6Now these things, brethren, I have figuratively applied to myself and Apollos for your sakes, so that in us you may learn not to exceed what is written, so that no one of you will become arrogant in behalf of one against the other. 1 Corinthians 4:6 NASB
30Therefore many other signs Jesus also performed in the presence of the disciples, which are not written in this book; 31but these have been written so that you may believe that Jesus is the Christ, the Son of God; and that believing you may have life in His name. John 20:30-31 NASB
If the Word is insufficient, as you appear to be suggesting, then it opens the door for the Mormon to use the Book of Mormon. Or the Muslim to use the Koran.
There has to be a standard...a canon if you will, for the church to measure all things. Much as the Bereans did.
This scripture jumped out to my mind
Now these things, brethren, I have figuratively applied to myself and Apollos for your sakes, so that in us you may learn not to exceed what is written, so that no one of you will become arrogant in behalf of one against the other.as an excellent answer to the statement "Jesus doesn't say, 'Just keep repeating EXACTLY the words and phrases that I spoke to you'"
1 Corinthians 4:6
And of course Jesus didn't say EXACTLY that to us, but made it clear to repeat His words to others so they may receive salvation and edification.
What He did NOT say was to vainly repeat "prayers" or extra-Biblical prayers writtings which greatly exceed that which was written and instructed by the Holy Spirit of God.
Notice how arrogance follows going against the Word of God.
Helps to understand the anger and hate that flies off of some keyboards when scripture and Biblical principles are expressed by Christians here to refute the false teachings of men.