Not quite: συγγενεις, with an iota after the epsilon, is actually the nominative plural of συγγενης, i.e. a merely different inflection of the same word (like “child” and “children”). As “people of the same clan (γενος)”, it refers to relatives in a very broad sense. It is also usable for brothers (cf. Sophocles’ Oedipus at Colonus 1387).
Thus, Paul, in Romans 9:3-4, uses συγγενης and αδελφος as synonyms, saying, ηυχομην γαρ αυτος εγω αναθεμα ειναι απο του χριστου υπερ των αδελφων μου των συγγενων μου κατα σαρκα, οιτινες εισιν ισραηλιται (“For I could wish that myself were accursed from Christ for my brethren, my kinsmen according to the flesh: Who are Israelites”). He thus uses αδελφος for others of his entire γενος, not just for members of his own household.
This exclusivity of denotation which you are trying to construct between αδελφος and συγγενης does not exist either in Greek or in biblical Greek. Thus, the fact that one is used in one verse and the other is used in another verse logically does not demonstrate that the verses refer to exclusive sets of people.
Again, I’m saying the “adelphos” exclusively is limited to uterine brothers. Rather, in the context of Mark 6:3 it does, because: a) it’s clear that the unbelieving Jew addressing Jesus is referring to His family unit (father, mother, brothers, sisters); & b) Jesus states that even members of
His Own household didn’t believe Him. This would eliminate His step-father & mother, which would only leave His brothers & sisters (adelphos & adelphe) which are not the same as His “syggenes” in in v.4.
Meanwhile, had the Gospel writers really wanted to say that they were Jesus’ half-brothers, other children of Mary, Greek
did have a term for consanguinity:
συναιμος.
Yet, the Greek uses the exact same Greek word to describe Peter’s “brother” Andrew, & Martha & Mary’s “brother” Lazarus. Numerous other examples in the NT can be given too.
Ανεψιος, of which I can find no other example in the NT than Paul’s usage in Col 4:10, refers particularly to cousins, a very specific type of relationship.
Actually, Vatican.va recognizes “syggenis” (with an “i” rather than an “e”) as “cousin” to describe Mary’s relationship to Elizabeth, which is a variation of “syggenes” to refer to relatives.
If the others mentioned were not the children of Jesus’ aunts or uncles, ανεψιος would be inappropriate. Both αδελφοι and συγγενεις, on the other hand, are broad enough to cover a whole range of people.
Again, this is why we have to consult the rest of Scripture to find out that Jesus’ brothers were His half-siblings.
Who was their mother? It is not particularly significant, since, as already pointed out, the NT does use αδελφος for people who had different mothers. I just cannot remember there being any reference to her.
It doesn’t matter. It’s clear that John was their father, which at the very least make them half-brothers, if not full-brothers. The point is that the same Greek word for “brother” is used for their relationship.
As previously noted, far from dismissing the possibility of αδελφοι referring to Mary’s other children, I have commented that such a thing is linguistically possible, but is not expressed in Scripture. Your assumption that it must be so is evidently based upon reading the English into the Greek, regardless of native speakers’ readings of it.
No, it’s based on examining EVERY passage of Scripture that discusses these “brothers” of Jesus - which there are many - to eliminate all the other possibilities of who these “adelphos” are. When you do that, you are left with them being half-brothers.
Sorry, but perhaps you missed my religious identification: I am not Catholic, and none of this comes from my religious views. It comes merely from reading the Greek.
My apologies of my assumption on your religious ID. However, I read the Greek too, and compare it to ALL of the Scripture verses pertaining to Jesus’ brothers, and based on both, Jesus had half-brothers, as well as half-sisters.