His parents want him to give up da’wah work
Question

                What is more important for a muslim man, to obey his parents or work for ummah?.

 Im asking this question because my husband has chosen to work to help other muslims with their deen and his parents do not agree. His father wants him to go back home and get a job on his original profession. I do not know what to do since his father wants me to convince my husband to do so. I am the only one in the family who supports my husband's choices for the sake of Allah. I have renounced my rights as a wife to allow him to proceed with his work. We have some difficulties, but Alhamdulillah, we are doing fine by the mercy of Allah SWT.

 What should be my behaviour? I do not wnat to disobey my father-in-law but I do not want to interfere in my husband's choices for life. We both have agreed with a simple life.
Praise be to Allah.
    Firstly: 

    There is no doubt that Allaah has enjoined obedience towards 
    parents. Allaah says (interpretation of the meaning): 

    “Say (O Muhammad): ‘Come, I will recite what your Lord has 
    prohibited you from: Join not anything in worship with Him; be good and 
    dutiful to your parents; kill not your children because of poverty’ — We 
    provide sustenance for you and for them. Come not near to Al-Fawaahish 
    (shameful sins and illegal sexual intercourse) whether committed openly or 
    secretly; and kill not anyone whom Allaah has forbidden, except for a just 
    cause (according to Islamic law). This He has commanded you that you may 
    understand”

    [al-An’aam 6:151]

    It was narrated that Abu Hurayrah (may Allaah be pleased with 
    him) said: A man came to the Prophet  (peace and blessings of Allaah be 
    upon him) and said, “O Messenger of Allaah, who is most deserving of my good 
    companionship?” He said, “Your mother.” He asked, “Then who?” He said, “Your 
    mother.” He asked, “Then who?” He said, “Your mother.” He asked, “Then who?” 
    He said, “Your father.”

    (Narrated by al-Bukhaari, 5626; Muslim, 2548). 

    It is haraam to disobey one's parents. It was narrated that 
    al-Mugheerah ibn Shu’bah said: The Prophet  (peace and blessings of 
    Allaah be upon him) said: “Allaah has forbidden you to disobey your mothers, 
    to bury infant girls alive, to withhold the rights of others, to demand what 
    is not rightfully yours, to pass on everything that you hear, to ask too 
    many questions and to waste money.”

    (Narrated by al-Bukhaari, 2277; Muslim, 593) 

    Working for Islam is obligatory upon a Muslim as much as he 
    is able to. Your husband may have to stay in the country to serve the 
    Muslims, teach them and take care of their affairs. Therefore your husband 
    should not go back to his country and give up calling people to Allaah and 
    working for the ummah. A man asked Shaykh ‘Abd al-‘Azeez ibn Baaz (may 
    Allaah have mercy on him): 

    For a number of years I have been teaching people to memorize 
    Qur’aan in a place far away from the city in which my parents live, and they 
    are asking me to stop teaching and work with one of my brothers who live 
    with them. I am hesitant about this matter because I am afraid that if I 
    stop teaching, the students will be neglected and will forget the Qur’aan 
    that they have memorized. What to you advise me to do? May Allaah reward you 
    with good. 

    He replied: 

    We advise you to continue teaching Qur’aan memorization, 
    because the Prophet  (peace and blessings of Allaah be upon him) said: 
    “The best of you are those who learn the Qur’aan and teach it to others” 
    (narrated by Imaam al-Bukhaari in his Saheeh); and because that is in 
    the general interests of the Muslims. You do not have to obey your parents 
    in giving that up, because the Prophet  (peace and blessings of Allaah 
    be upon him) said: “Obedience is only with regard to what is good and 
    proper.” But it is prescribed for you to explain that to them in a kind and 
    polite manner. 

    And Allaah is the Source of strength.

    Majmoo’ Fataawa al-Shaykh Ibn Baaz, 
    5/412 

    Secondly: 

    Your husband could obey his parents and return to his country 
    if there is someone who could take his place in working for Islam there and 
    if there is also a need to work for Islam in the country where his family 
    is. In this manner he can do two things at once, fulfilling his father’s 
    wishes and also working for Islam. His own country may be in greater need, 
    and his staying in the country where he is now may not allow him to practise 
    Islam openly or raise his children in Islam.

     But if your husband will be coming back to work in his 
    specialty without working for Islam, then you should be on his side and 
    encourage him to stay and work for Islam. Undoubtedly this will be good for 
    you in religious terms, if not in worldly terms. For what is with Allaah is 
    better and more lasting. We should also note that a person is not like a 
    candle and should not burn himself to provide light for others. If the 
    environment in which he is does not help him to obey Allaah and give your 
    children a sound Islamic upbringing, then try to change it and move to a 
    good environment where your children can grow up in Islam. May Allaah help 
    us all to do that which He loves and which pleases Him. And Allaah knows 
    best.