Just going to throw in a my 2 cents. I read through this thread and the comments and I want to add something.
I am member of a church of Christ, believe in Sola Scriptural and I am married to a Catholic, needless to say some of our discussions are very interesting.
I grew up 100% believing that Jesus had younger siblings, whom were fully blooded, at least 4 brothers and 2 sisters. Giving him a huge family! It was never brought up as a “this is why Catholics are wrong” but as part of various Sunday school classes discussing Jesus and his family.
As I have spent more time studying to figure out if He did or didn’t have siblings, I found the following.
Matt 13:55 specifically mention His mother Mary and His brothers, James, Joseph, Simon and Judas.
And verse 56 then says “Are not His sisters all with us?”
This tells me a couple of things, 4 brothers, and a plurality of sisters (more then 2). So that fits with what I was taught growing up.
Galations also mention James being his Brother.
Mark 6:3 is also a mention that is another aspect of Matt 13.
Now I know the Catholic belief would be ok with 2 possibilities for the brothers and sisters. Either they were Joseph’s kids from an earlier marriage, so older siblings. Or they we Jesus’ cousins. Given the mention of Mary as His Mother in Mat 13:55, I think that would lend a more literal meaning of the 4 as brothers, especially since if they were His cousins, wouldn’t His Aunt also be mentioned?
But just the fact that Mary is mentioned and the brothers and sister lend credence to the idea they aren’t cousins.
So that leaves us with older siblings being Josephs kids from a previous marriage. However as couple of ppl mentioned, wouldn’t they be mentioned in the travels for the census or the fleeing to Egypt? Not necessarily, because they aren’t the focal point of those stories, but it does seem odd that they wouldn’t mention them in a genealogy or something. So thats a possibility,
I guess, its also possible that Joseph could have cheated on Mary….but I won’t even go there, because its a pretty dumb idea.
But you know what i have realized? If He had siblings or not doesn’t matter. Would Mary having sex with her husband lower her at all? Make her unworthy of carrying Jesus? Mean she wasn’t full of grace?
No, Jesus’ mother had to be Virgin when Jesus was to fulfill prophecy, but nothing says she had to remain so, at least in the Bible canon. Does it matter at all? Not really, I don’t even think Catholic doctrine would ding Mary for having sex and kids. She is still full of grace, still a women that was good enough to carry God’s Son, and would still be a good role model for every woman to aspire to be like.
Just my 2 cents.