“And Jesus came and spoke to them, saying, ‘All authority has been given to Me in heaven and on earth,’” Matt 28:18-19.
Jesus is the authority in the church and in the world, as all authority has been given to him by the Father.
“I still have many things to say to you, but you cannot bear them now. 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. He will glorify Me, for He will take of what is Mine and declare it to you. All things that the Father has are Mine. Therefore I said that He will take of Mine and declare it to you,” John 16:12-15.
Jesus plainly states that the New Testament is written on his authority, as the Spirit did not teach from himself, but from Christ.
“Hold fast the pattern of sound words which you have heard from me, in faith and love which are in Christ Jesus,” 2 Tim 1:13.
We are instructed to hold fast to the pattern we have heard from Christ (obviously what Paul taught is from Christ).
“Whoever therefore breaks one of the least of these commandments, and teaches men so, shall be called least in the kingdom of heaven; but whoever does and teaches them, he shall be called great in the kingdom of heaven. For I say to you, that unless your righteousness exceeds the righteousness of the scribes and Pharisees, you will by no means enter the kingdom of heaven,” Matt 5:19-20.
Jesus states that if we don’t teach as he taught us, we will not enter heaven.
“But even if we, or an angel from heaven, preach any other gospel to you than what we have preached to you, let him be accursed. As we have said before, so now I say again, if anyone preaches any other gospel to you than what you have received, let him be accursed,” Gal 1:8-9.
Paul plainly states that there is no other doctrine in the kingdom of Christ other than what we have in the inspired writings of the New Testament.
“Anyone who goes too far and does not abide in the teaching of Christ, does not have God; the one who abides in the teaching, he has both the Father and the Son. If anyone comes to you and does not bring this teaching, do not receive him into your house, and do not give him a greeting; for the one who gives him a greeting participates in his evil deeds,” 2 John 9-11.
John agrees with Paul, stating that anyone who does not abide in the doctrine in the New Testament does not have God, but rather works evil.
"And the Lord said to me: 'What they have spoken is good. I will raise up for them a Prophet like you from among their brethren, and will put My words in His mouth, and He shall speak to them all that I command Him. And it shall be that whoever will not hear My words, which He speaks in My name, I will require it of him,” Deut 18:17-19.
“He who rejects Me, and does not receive My words, has that which judges him — the word that I have spoken will judge him in the last day. For I have not spoken on My own authority; but the Father who sent Me gave Me a command, what I should say and what I should speak. And I know that His command is everlasting life. Therefore, whatever I speak, just as the Father has told Me, so I speak,” John 12:48-50.
Moses prophesied, and Jesus confirmed, that we will be judged by the words that Jesus has spoken, both when he was on earth, speaking by the authority of the Father, and by the New Testament, authored by the Spirit by the authority of Christ.