Paul Is About Mystery, Jesus Is About Truth
Paul is all about mysteries. He uses the word 'mystery' seventeen times in his epistles. Excluding the Book of Revelation, the word 'mystery' is used only one other time in the Bible: And [Jesus] said unto them, Unto you it is given to know the mystery of the kingdom of God: but unto them that are without, all these things are done in parables.Mark 4:11
Paul claims he is the sole person who can reveal these mysteries. Now to him that is of power to stablish you according to my gospel, and the preaching of Jesus Christ, according to the revelation of the mystery, which was kept secret since the world began.Romans 16:25 How that by revelation he made known unto me the mystery; (as I wrote afore in few words, Whereby, when ye read, ye may understand my knowledge in the mystery of Christ).Ephesians 3:3-4 And to make all men see what is the fellowship of the mystery, which from the beginning of the world hath been hid in God, who created all things by Jesus Christ.Ephesians 3:9 And for me, that utterance may be given unto me, that I may open my mouth boldly, to make known the mystery of the gospel, for which I am an ambassador in bonds: that therein I may speak boldly, as I ought to speak. Ephesians 6:19, 20 Even the mystery which hath been hid from ages and from generations, but now is made manifest to his saints: To whom God would make known what is the riches of the glory of this mystery among the Gentiles; which is Christ in you, the hope of glory.Colossians 1:26-27 That their hearts might be comforted, being knit together in love, and unto all riches of the full assurance of understanding, to the acknowledgement of the mystery of God, and of the Father, and of Christ; in whom are hid all the treasures of wisdom and knowledge.Colossians 2:2-3
Consider what Paul is writing. He is writing that he, Paul, has been given the ability and responsibility to "make known the mystery of the gospel." One would that that based on Jesus's saying,Mark 4:11 that Paul would be explaining Jesus's parables. But he is not. Paul is saying he is the one in charge of making sure these mysteries are known, and that by these mysteries, one gets to go to heaven. He ignores Jesus's parables altogether.
God is not the God of confusion. Jesus spoke only the truth. Jesus also only spoke what God gave to him to say.
Thus, how can there be many mysteries to speak of? Did Jesus not tell His disciples everything? If that is the case, then why did Jesus say, I have given them thy word; and the world hath hated them, because they are not of the world, even as I am not of the world…. Sanctify them through thy truth: thy word is truth.John 17:14, 17
Did God suddenly have new words and new opinions on the gospel? Is that why God had his beloved son Jesus come to an enemy of Jesus, to preach this new interpretation of the gospel? No. There is no reason that Paul should make a claim of all the "mysteries" of Christ, faith, God, and so forth.
Value of this Evidence
This is significant evidence against Paul's case of being a true apostle. No real apostle would dare to change the gospel that Jesus came to earth to preach.