Are ongoing sins, such as when someone teaches their children evil and then dies while they persist in it, accounted against the deceased?

If a servant dies having committed acts that violate the Sacred Law, and others followed his example in these acts, then he bears the burden of what he did, and the burden of those who acted upon his example, without any diminution of their own burdens.

The Messenger of Allah, peace and blessings be upon him, said: "Whoever introduces a bad practice in Islam, and it is acted upon after him, then a burden similar to that of those who acted upon it will be written upon him, without any diminution of their burdens." This includes anyone who innovates something evil; he bears the burden of everyone who follows his example until the Day of Judgment.

Thus, a father who raised his children poorly and was a bad example for them, and they followed his deviant behaviors, bears their burden, while they themselves are responsible for their actions.

The Messenger of Allah, peace and blessings be upon him, said: "All of you are shepherds, and all of you are responsible for your flock... And a man is a shepherd over his household and is responsible for his flock." Therefore, he must take the best care of them, for he is responsible for them.