Their father is active in da’wah but they are complaining about his bad treatment of his family
Question

                My father goes with jamaat etc, and spends a lot of time in markez and mosque. But when he is home he is only arguing with his family. Especially his wife, he treats her as the lowest thing on earth, and he never lkistend to her. He evenmade her break contacts with her side of the family, and she is very hurt and cries a lot. In his eyes he is better than her family etc. He never listens to any of us. He says what he says is right and that Islam agrees with him. This is not right because Islams shouldnt agree with anyone, we should agree with Islam. And Islam does not teach to not listen to your wife and argue and not treat your wife in a right way. We do not know what to do, it is like he is terrorising us. He neve speaks to any of us in a normal way, its only like get me this or get me that, and else he will only but comment us for anything, like why are you holding a pen like that, the strangest things. But the most is that he is hurting my mum, by acting like this, and she is already ill. I am desperate, and so is my family, we dont know what to do. Please help us as son as you can, please.
Praise be to Allah.The Muslim must develop a good attitude and commendable conduct. He has to avoid the things that incur the wrath of Allaah, and say only that which is best. Allaah says (interpretation of the meaning): 
“And say to My slaves (i.e. the true believers of Islamic Monotheism) that they should (only) say those words that are the best. (Because) Shaytaan (Satan) verily, sows a state of conflict and disagreements among them. Surely, Shaytaan (Satan) is to man a plain enemy”
[al-Isra’ 17:53]
The Messenger of Allaah (peace and blessings of Allaah be upon him) said: “The believer does not slander, curse, or speak in an obscene or foul manner.” Narrated by al-Tirmidhi, 1977, from the hadeeth of ‘Abd-Allaah ibn Mas’ood. Classed as saheeh by Ibn Hibaan, 1/421; al-Haakim, 1/57; al-Albaani in Saheeh al-Jaami’, 5381. 
It was narrated that Abu’l-Darda’ (may Allaah be pleased with him) said: The Messenger of Allaah (peace and blessings of Allaah be upon him) said: Allaah hates the obscene, foul-mouthed person.” Narrated and classed as saheeh by al-Tirmidhi, 2002. 
Al-San’aani said: 
This hadeeth tells us that swearing and cursing are not characteristics of the true believer, but an exception is made in the case of cursing kaafirs, drinkers of alcohol and those whom Allaah and His Messenger cursed. 
Subul al-Salaam, 4/198. 
So the believer has to develop the attitude described in the Qur’aan, and the attitude exemplified by the Prophet (peace and blessings of Allaah be upon him), especially towards his family. The Messenger of Allaah (peace and blessings of Allaah be upon him) said, “The best of you is the one who is best to his family.” 
Al-Shawkaani (may Allaah have mercy on him) said: 
Here we are told that the best of the people are those who are best towards their families because the family are the ones who most deserve to cheerfulness, good attitude and kindness; benefits should be brought to them and harm warded off from them. If a man is like that then he is the best of people, but if he is the opposite then he is the worst type. People often make this mistake, so you see a man who, when he meets his family he treats them in the worst and most unkind manner, and when he meets strangers who are not part of his family, he is gentle and polite and kind to them. Undoubtedly a person who is like that is deprived of divine support and is going astray from the straight path. We ask Allaah to keep us safe and sound.  
Nayl al-Awtaar, 6/360. 
The group with whom your father is going out is well known for having and promoting good characteristics, so the basic principle is that he is like that too, and that he fears Allaah. We say to you – if what you say about your father is true – that this is a test, and you have to be patient and pray that Allaah will guide him to the best of attitudes and characteristics. 
Patience undoubtedly brings a great reward. His wife must also be patient and put up with her husband’s annoyance, and obey him with regard to that which Allaah has permitted. If he is forbidding her to visit her relatives for a legitimate shar’i reason, then he has the right to do that, but if there is no legitimate reason then she has to obey him, but he is sinning, and the wife will be rewarded in sha Allaah. 
More advice may be found in the answer to question no. 482. We advise you to look at that, and we advise both husband and wife to read the answer to question no. 10608, which explains the rights of each spouse over the other. 
And Allaah knows best.