In your opinion, are all the righteous Jews of the Old testament inhell, ad a result of NOT believing in Jesus Christ
?
Sincere question.
How about all the little baby boys murdered in Bethlehem by Herod?
The question may be ill posed.
Nobody in humanity, save for Christ who independently became man, is innocent — due to joint spiritual participation in the fall of mankind.
That said, we have assurances such as “The Lord does not willingly grieve the sons of men.” The dear evangelical pastor of the bible church I used to go to put it this way — if a soul would be willing, the Lord will arrange for a witness somehow.
The question for the believing Christian is, not to worry about people going to hell in the collective (which is vain) but will you be willing to be such a witness (which is NOT vain).
Babies are not “accountable.”
And this link will give a better explanation on the other point than I could.
https://gotquestions.org/Old-Testament-believers.html