Not entirely, for Joseph isn't biologically related to Jesus, though still family.
Although Jesus wasn't biologically Joseph's son, because He was begotten by the Holy Spirit (Lk. 1:35).
We know Mary of Joseph is Jesus's biological Mother because of Lk. 1:31.
Joseph, Simon, James, and Judas (Jude/Thaddeus) are never called the sons of Joseph and/or Mary of Joseph, but rather Jesus's "
adelphoi" (sing. adelphos; pl.
ἀδελφοὶ adelphoi), or "
brothers" in English, in Matt. 13:55/Mk. 6:3, and that doesn't prove they were His siblings, because the word has multiple definitions, e.g., "fellow-countryman", "disciple/follower", "one of the same faith", and "near kinsman, or relative", etc.
We agree the definition that applies to the word "
adelphoi" in Matt. 13:55/Mk. 6:3 is "near kinsman, or relative", but a kinsman/relative can be a sibling, cousin, nephew, or uncle, etc., and the word itself doesn't indicate which type of kinship applies. For this reason, merely citing verses with the word "
adelphoi" and basically saying "See, they were Jesus's
siblings!" is assuming that type of kinship applies, but
an assumption isn't proof.
Unlike you and others, I don't
assume my position is true, I s
how it is, and my position is that Joseph, Simon, James, and Judas (Judas/Thaddeus) were the sons of Joseph's brother, Alphaeus, and his wife Mary of Alphaeus (Clopas/Cleophas), and thus were Jesus's brothers, as in kinsmen, specifically His cousins. See
here.
The unnamed sisters of Jesus are never called the daughters of Joseph and/or Mary of Joseph, but rather only Jesus's "
αδελφαι" (sing. adelphē; pl. αδελφαι adelphai), or "sisters" in English, and that doesn't prove they were His siblings, because the word has multiple definitions, one of them being "near kinsman, or relative".
We agree the definition that applies to the word "
αδελφαι" in Matt. 13:56/Mk. 6:4 is "near kinsman, or relative", but a kinsman/relative can be a sibling, cousin, niece, or aunt, etc., and the word itself doesn't indicate which type of kinship applies. For this reason, merely citing verses with the word "
αδελφαι" and basically saying "See, they were Jesus's
siblings!" is assuming that type of kinship applies, but
an assumption isn't proof.
Correct, you only err in your assumption of the
type of kinsmen, or relatives, that Joseph, Simon, James, and Judas (Judas/Thaddeus) were to Joseph, Mary of Joseph, and Jesus.
As I've shown, Joseph, Simon, James, and Judas (Jude/Thaddeus) were the sons of Joseph's brother, Alphaeus, and his wife Mary of Alphaeus (Clopas/Cleophas), and thus were the nephews of Joseph and Mary of Joseph, and cousins of Jesus. See
here.
The word used in Lk. 2:7 is "
πρωτότοκος" (prōtotokos), or "firstborn" in English, and it has more than one definition. You "presume" the definition "eldest" applies, but this
"presumption" is based on the
assumption Joseph, Simon, James, and Judas (Jude/Thaddeus) were Jesus's siblings, and
an assumption isn't proof.