In context this scripture is a direct quote from Jesus in answer to a question posed to him by one of his apostles....
“In answer Jesus said to him: “If anyone loves me, he will observe my word, and my Father will love him, and we will come to him and make our dwelling with him. 24 Whoever does not love me does not observe my words. The word that you are hearing is not mine, but belongs to the Father who sent me.
25 “I have spoken these things to you while I am still with you. 26 But the helper, the holy spirit, which the Father will send in my name, that one will teach you all things and bring back to your minds all the things I told you. 27 I leave you peace; I give you my peace. I do not give it to you the way that the world gives it. Do not let your hearts be troubled nor let them shrink out of fear. 28 You heard that I said to you, ‘I am going away and I am coming back to you.’ If you loved me, you would rejoice that I am going to the Father, for the Father is greater than I am. 29 So now I have told you before it occurs, so that you may believe when it does occur. 30 I will not speak with you much more, for the ruler of the world is coming, and he has no hold on me. 31 But for the world to know that I love the Father, I am doing just as the Father has commanded me to do.” (John 14:23-31)
John was quoting Jesus’ own words, which he said had come from his Father. We would not ever know what Jesus said if the apostles and other Bible writers had not recorded them. Do you not believe that God is powerful enough to oversee the recording and preservation his word from contamination? I do......
Interpretation is another matter.
There is no guesswork....the apostle John was a close companion of Jesus throughout his entire ministry. What is recorded is there because God, by his spirit, chose what was to be included in Christian scripture. Those who are not Christians are not in a position to question what is God’s word and what is not.
Are you a Christian? If not, then what is included in Christian scripture is not your scripture...just as what is included in Islamic scripture is not our scripture....and what is included in Hindu writings is not our scripture either. We choose what we accept as scripture for our own reasons, and God allows us to choose because that is how he judges us....our heart’s response to his truth. No ne can come to God and except through Jesus, and no matter ne can come to Jesus without an invitation from the Father. (John 14:6; John 6:44, 65)
Are you telling me or asking me? I am telling you as a Christian and a student of God’s word, that you are mistaken. The apostle John was inspired by God’s spirit to recall and record what were the most important aspects of his personal experience with Jesus. All of the apostles were, including Paul, who was personally selected by Jesus for a special assignment...to take the Christian message to the gentile nation’s. He was educated and enjoyed the benefits of Roman citizenship, which in that assignment was advantageous.
Who are you to question any of that? Who is Jesus to you? Merely a prophet?...or the son of God who was sent from heaven to redeem mankind? Please....?