How can one deal with a father who abuses his children and wife, and does not provide for them, while the children attempt to honor their mother who sacrificed for them?

You must honor your parents and not mistreat your father, no matter how much he may mistreat you or your mother, for the right of a father is great. It is not a condition for righteousness that you be a friend to your father; rather, it is sufficient that you fulfill his rights, obey him in what is good, and speak to him gently and respectfully. If your father mistreats your mother, advise him gently and kindly, or intercede through someone who can advise him. Beware lest anger lead you to mistreat him, and strive against your own self, be patient, and seek help from Allah. Honoring your father and being good to him are among the best deeds and the most beloved to Allah, for in them lies the Lord's pleasure, and the father is the middle gate of Paradise.