Several of Paul’s EPISTLES are considered forgeries in the sense they are written in a style unlike the others, Timothy I and II are universally accepted as having been written by someone other than Paul. Romans I and II are considered authentic. We have actual letters written by Paul who met with both Peter and James, witnesses, Jesus’ apostles. There can be no doubt Paul believed them.
Since you're not going to engage anyway I broke it down "I got your nose style" (just in case) for others to see.
The earliest Christian writings the 7 nonpseudographical Pauline epistles are odd when looked at closely.
Paul is adamant that his Gospel is not from humans, but from scripture, and visions/dreams.
Galatians (NRSV) 1:11-12, :15-17 "11 For I want you to know, brothers and sisters, that the gospel that was proclaimed by me is not of human origin; 12 for I did not receive it from a human source, nor was I taught it, but I received it through a revelation of Jesus Christ"
"15 But when God, who had set me apart before I was born and called me through his grace, was pleased 16 to reveal his Son to me, so that I might proclaim him among the Gentiles, I did not confer with any human being, 17 nor did I go up to Jerusalem to those who were already apostles before me, but I went away at once into Arabia, and afterwards I returned to Damascus."
Romans 15:4 "4 For whatever was written in former days was written for our instruction, so that by steadfastness and by the encouragement of the scriptures we might have hope."
1 Corinthians 15:3-8 "3 For I handed on to you as of first importance what I in turn had received: that Christ died for our sins in accordance with the scriptures, 4 and that he was buried, and that he was raised on the third day in accordance with the scriptures,"
Note: Exodus 19:11, :15-16 "11 and prepare for the third day, because on the third day the LORD will come down upon Mount Sinai in the sight of all the people.; "15 And he said to the people, "Prepare for the third day; do not go near a woman. 16 On the morning of the third day there was thunder and lightning, as well as a thick cloud on the mountain, and a blast of a trumpet so loud that all the people who were in the camp trembled." Mark 16:8 (women visiting the tomb) "8 So they went out and fled from the tomb, for terror and amazement had seized them; and they said nothing to anyone, for they were afraid."
A secret hidden through the ages now revealed from scripture, and the spiritual realm (their imagination).
Romans 16:25-26 "25 Now to God who is able to strengthen you according to my gospel and the proclamation of Jesus Christ, according to the revelation of the mystery that was kept secret for long ages 26 but is now disclosed, and through the prophetic writings is made known to all the Gentiles, according to the command of the eternal God, to bring about the obedience of faith —"
1 Corinthians 2:7, :13 "7 But we speak God's wisdom, secret and hidden, which God decreed before the ages for our glory."; "13 And we speak of these things in words not taught by human wisdom but taught by the Spirit, interpreting spiritual things to those who are spiritual."
Also Paul says his apostleship is by the same means as the founding Pillars.
Galatians 2:6-9 "6 And from those who were supposed to be acknowledged leaders (what they actually were makes no difference to me; God shows no partiality) — those leaders contributed nothing to me. 7 On the contrary, when they saw that I had been entrusted with the gospel for the uncircumcised, just as Peter had been entrusted with the gospel for the circumcised 8 (for he who worked through Peter making him an apostle to the circumcised also worked through me in sending me to the Gentiles), 9 and when James and Cephas and John, who were acknowledged pillars, recognized the grace that had been given to me, they gave to Barnabas and me the right hand of fellowship, agreeing that we should go to the Gentiles and they to the circumcised."
Scholars like Bart Ehrman say that since Paul met Jesus's brother James then there's no doubt for historicity. What such scholars leave out is Paul never specifically says it's a blood relation which is fair enough because Paul's audience would know what he's talking about. The big omission is the foundational theology in Christianity of spiritual adoption which has Paul calling everyone in the familiar that are not blood related to him. The phrase "LORD'S brother" could be just an idiom, or rank/title the cult used (Gal. 1:19 "but I did not see any other apostle except James the LORD's brother.").
Galatians 1:1 "1 Paul an apostle — sent neither by human commission nor from human authorities, but through Jesus Christ and God the Father, who raised him from the dead — 2 and all the members of God's family who are with me,"
Galatians 3:26-29, 4:5-7 "26 for in Christ Jesus you are all children of God through faith. 27 As many of you as were baptized into Christ have clothed yourselves with Christ. 28 There is no longer Jew or Greek, there is no longer slave or free, there is no longer male and female; for all of you are one in Christ Jesus. 29 And if you belong to Christ, then you are Abraham's offspring, heirs according to the promise." (Gen. 12:1-3, 17:4-6)
"5 in order to redeem those who were under the law, so that we might receive adoption as children. 6 And because you are children, God has sent the Spirit of his Son into our hearts, crying, "Abba! Father!" 7 So you are no longer a slave but a child, and if a child then also an heir, through God."
Romans 8:12-15 "12 So then, brothers and sisters, we are debtors, not to the flesh, to live according to the flesh — 13 for if you live according to the flesh, you will die; but if by the Spirit you put to death the deeds of the body, you will live. 14 For all who are led by the Spirit of God are children of God. 15 For you did not receive a spirit of slavery to fall back into fear, but you have received a spirit of adoption. When we cry, "Abba!"'
The first we hear of Jesus having a brother named James is later in Mark. In chapter 3 Jesus rejects his family for a spiritual family (Rom.8:14). In chapter 6 the anonymous author uses heavy irony. What, and where did he get wisdom (1 Cor. 1:24b "Christ the power of God and the wisdom of God."). What deeds of power done by his hands, and he's a craftsman/tekton (Rom. 11:36ab "For from him and through him and to him are all things.", 1 Cor. 8:6cd "one Lord, Jesus Christ, through whom are all things and through whom we exist."). Then we get the (anglicized) Tom, Dick, and Harry of ancient Judea (common names). Mark is highly allegorical, and shows signs of literay artifice.
Mark 3:31-32 , 6:2-3 "31 Then his mother and his brothers came; and standing outside, they sent to him and called him. 32 A crowd was sitting around him; and they said to him, "Your mother and your brothers and sisters are outside, asking for you." 33 And he replied, "Who are my mother and my brothers?" 34 And looking at those who sat around him, he said, "Here are my mother and my brothers! 35 Whoever does the will of God is my brother and sister and mother."'
"2 On the sabbath he began to teach in the synagogue, and many who heard him were astounded. They said, "Where did this man get all this? What is this wisdom that has been given to him? What deeds of power are being done by his hands! 3 Is not this the carpenter, the son of Mary and brother of James and Joses and Judas and Simon, and are not his sisters here with us?" And they took offense at him."
Philo has spiritual family philosophies as well.
Philo: ON THE CONFUSION OF TONGUES
"XI ...In reference to which I admire those who say, “We are all one man’s sons, we are men of Peace,” (Gen. 42:11) because of their well-adapted agreement; since how, I should say, could you, O excellent men, avoid being grieved at war, and delighted in peace, being the sons of one and the same father, and he not mortal but immortal, the man of God, who being the reason of the everlasting God, is of necessity himself also immortal?"
"XXVIII ...And even if there be not as yet any one who is worthy to be called a son of God, nevertheless let him labour earnestly to be adorned according to his firstborn word, the eldest of his angels, as the great archangel of many names; for he is called, the authority, and the name of God, and the Word, and man according to God’s image, and he who sees Israel. For which reason I was induced a little while ago to praise the principles of those who said, “We are all one man’s Sons.” (Gen. 42:11) For even if we are not yet suitable to be called the sons of God, still we may deserve to be called the children of his eternal image, of his most sacred word; for the image of God is his most ancient word...."