Is a young person who did not find someone to teach him matters of his religion in his youth to be blamed for the actions he committed in his adulthood, and will Allah Almighty hold him accountable like any person who received religious upbringing?

Parents have a significant impact on raising children, and the righteousness of parents may be a cause for the righteousness of their children, but it is not a necessity. Many righteous people have corrupt children, and vice versa. Noah, peace be upon him, had a disbelieving son. Thus, the reasons for guidance are not limited to the righteousness and guidance of parents. Young people are blameworthy for committing forbidden acts if they know their prohibition, or if they were able to know and turned away from it. However, merely having bad upbringing circumstances is not an excuse for committing forbidden acts. And whoever insists on falsehood while there is someone to explain the truth to him is more sinful than someone who did not find a guide.