This thread is directed at those who claim both the following:
(i) that Joseph, Simon, James, and Judas (Jude/Thaddeus) in Matt: 13:55/Mk. 6:3 were Jesus's siblings
(ii) that James of the four in Matt: 13:55/Mk. 6:3 and James in Gal. 1:19 were the same person
In Gal. 1:18-19, it's indicated by Paul that James was both an apostle of the Twelve
and a family member of Jesus. The reason being that after Paul mentions
he had seen the
apostle Peter, one of
the twelve apostles, in Jerusalem, he continues to say that
he didn't see any of the other apostles,
except James. The context of Gal. 1:18-19 is w
hat indicates that James was one of the twelve apostles. It's the title "the Lord's brother" that follows James's first name that indicates he was also Jesus's family member.
The flaw in your believing that James in Gal. 1:19 was James of the four "siblings" of Jesus in Matt. 13:55/Mk. 6:3 is that the former was one of
the Twelve, which means that he had he had to have been either James of Zebedee or James of Alphaeus, and neither of them were a son of Joseph and Mary.
Therefore, I've proven the belief that Joseph, Simon, James, and Judas (Jude/Thaddeus) in Matt. 13:55/Mk. 6:3 were Jesus's siblings to be false using Scripture alone, but if you continue to repeat it as true, then I'll continue to challenge you to refute the evidence to the contrary in this post. If you have a
sliver of conviction in your belief, then you'd attempt to try.
Note: This in itself does not prove Mary of Joseph was a perpetual Virgin, though there are reasons that show She is.
However, you are still right about two things: that James in Matt. 13:55/Mk. 6:3 was Jesus's family member, and that he and apostle James of the Twelve in Gal. 1:19 were the same person, who again, was either apostle James of Zebedee or apostle James of Alphaeus. So, what type of family member would either apostle James of Zebedee, or apostle James of Alphaeus, have been to Jesus?
The answer is here, and in short, there I've shown that James in Matt. 13:55/Mk. 6:3, James in Gal. 1:19, and the apostle James of Alphaeus, etc., were the same person, and that he and his siblings Joseph, Simon, and Judas (who I've also shown was the apostle Judas of Alphaeus) were the sons of Joseph's brother, Alphaeus, and thus Jesus's cousins. And, they were called Jesus's "ἀδελφοί" (sing. ἀδελφός adelphos; pl. ἀδελφοὶ adelphoi), or "brothers" in English, and because the information I provided in the previously cited link shows they were His family, specifically cousins, that's why its definition "a near kinsman, or relative," which can and has been used to refer to various types of kin, including cousin, applies.