Hey @Tim_Ramey, I want to see if I can parse your question, and then maybe provide a thought about how we might best understand the John 9:2 passage. As has been referenced many times now, John 9:1-2 reads:
As he passed by, he saw a man blind from birth. And his disciples asked him,“Rabbi, who sinned, this man or his parents, that he was born blind?”
As we read the disciples question, they present two possible causes for the man’s blindness: (A) that the man sinned or (B) that the parents sinned.
The difficulty here, as I understand your question, is how to understand (A) because the man’s affliction came at, or prior to, birth, and the cause must have come prior to the effect. Better yet, your question is, how would the Jews have understood possibility A, as there only seem two rather strange possible explanations for this cause:
A1: the man somehow sinned in utero causing him to be born blind
or A2: the man sinned in a previous life and was reincarnated into this blind person’s body
And you, as do I, are hesitant to admit to a Jewish belief in either reincarnation or in utero sin. Hopefully, I have charted out your question sufficiently! If not, please do correct me, but if so, I’m now going to give my thoughts on how we might go about better understanding this question.
In short, I believe that we have two false dichotomies.
The first dichotomy comes in choosing between A1 and A2; I don’t believe that either is correct, and so I want to posit A3 (or perhaps ~A) which is that it is not the case the man’s sin caused his blindness. Now, this resolves, I believe your qualms with the Jews believing in A1 or A2. Quite simply, the Jews didn’t have to believe in either; they did not believe it to be a live option that the man’s sin could have caused the blindness prior to his birth. However, this presents us with another difficulty, because if ~A, then B; or rather, if the man’s sin didn’t cause the blindness, then the parent’s sin caused the blindness. But this too doesn’t seem right!
And this leads me to the second false dichotomy: I believe that our options between A, the man’s sin causing his blindness, and B, the parent’s sin causing the man’s blindness are a false dichotomy. Now, it isn’t any fancy logic that gets us to that conclusion, it is in reading verse 3:
Jesus answered, “It was not that this man sinned, or his parents, but that the works of God might be displayed in him.
We see that Jesus has replied that the question presented a false dichotomy, and there was some other cause for the man’s blindness. This does open up some more questions as we try to understand what it means that the man’s blindness shows the works of God, but that is for another conversation topic. I simply wanted to show that I think that the disciples, in asking this question of A or B, did not believe that either A or B were live options, but they couldn’t conceive of any alternative cause. And if they didn’t believe that A was a live option, that gives you an answer on why this passage wouldn’t be any manner of justification for support in a Jewish belief in reincarnation.
Does that make sense? I hope I haven’t jumbled things too much in my attempt at an explanation! I also apologize if I didn’t address all the parts of your question, but I think it at least starts us down the right track! What do you think? Do you think your brother and sister would see this as undermining a scriptural proof of reincarnation?