Some people make a great deal of du’aa’ but receive no answer
Question

                What is the reason for the delay in response to du’aa’? Some people make du’aa’ but they do not get any response; they ask for a long time but do not see it having any effect, so you find the Shaytaan starting to whisper to such people and making them think badly of their Lord.
Praise be to Allah.
      Firstly: 

    The one to whom that happens should believe that there is a 
    reason and great wisdom behind the delay in the response. Allaah, may He be 
    glorified, is the Sovereign of all and none can put back His bounty or 
    overturn His ruling or object to His giving or His withholding, if He gives 
    by His bounty or withholds by His justice. We are His slaves and He does 
    with us whatever He will. 

    “And your Lord creates whatsoever He wills and chooses, no 
    choice have they (in any matter)”

    [al-Qasas 28:68]

    How can a slave fall short in honouring his master’s rights 
    and then demand his rights in full? 

    It is His right to be obeyed and not disobeyed, to be 
    remembered and not forgotten, to be thanked and not to be shown ingratitude. 
    If you look at yourself and how you are carrying out your duties, you would 
    think very little of yourself and you would feel humility and would realize 
    there can be no salvation except by His forgiveness and mercy. So look at 
    yourself as being a slave, for Allaah is the Creator and Controller. 

    Secondly: 

    Allaah has great wisdom and He does not give or withhold 
    except for a reason. You may look at something and think that it is good but 
    by His wisdom He does not decree it. A doctor may do things which appear to 
    be painful but they are in the patient’s best interests. And for Allaah is 
    the highest description. (cf. al-Nahl 16:60). 

    Thirdly: 

    Attainting the thing asked for may cause hardship to the one 
    who is asking. It was narrated from one of the salaf that he used to ask 
    Allaah to let him go out on a military campaign, but a voice called out to 
    him: “If you go on a military campaign you will be taken prisoner, and if 
    you are taken prisoner, you will become a Christian.” Sayd al-Khaatir, 
    1/109 

    Ibn al-Qayyim said: Whatever Allaah has decreed for His 
    believing slave is a blessing even if that is in the form of withholding; it 
    is a favour even if that is in the form of a trial, and the calamity decreed 
    by him is fair even if it us painful. Madaarij al-Saalikeen, 4/215. 

    No one knows how his affairs will end up. He may ask for 
    something which leads to bad consequences, and may even harm him. The 
    Controller knows best what is in his best interests. “and it may be that 
    you dislike a thing which is good for you” [al-Baqarah 2:216]. One of 
    the meanings of this verse is that we should not wish that the decree of our 
    Lord was different or ask Him for things of which we have no knowledge, for 
    perhaps that may harm us without us knowing. So we should not choose 
    anything different than what our Lord has chosen for us, rather we should 
    ask Him for a good end in what He has chosen for us, for there is nothing 
    more beneficial for us than that. 

    Fourthly: 

    What Allaah chooses for His slave is better for him that what 
    he chooses for himself. Allaah is more merciful towards His slaves than they 
    themselves or their mothers are. If something happens to them that they 
    dislike, that is better for them than if it did not happen, so His decree is 
    all kindness and mercy. If the slave submits to Allaah and has certain faith 
    that all dominion belongs to Allaah and all things are under His command, 
    and that He is more merciful to him than he is himself, then he will find 
    peace of mind regardless of whether his need is met or not. 

    See Madaarij al-Saalikeen, 2/215 

    Fifthly: 

    The response may be delayed because the person himself has 
    done something which is an impediment to receiving a response or a cause of 
    delay. Perhaps there is something haraam in his food, or perhaps there was 
    some negligence in his heart at the time when he made the du’aa’, or perhaps 
    he had committed a sin, as a consequence of which his du’aa’ was not 
    answered. So when the response to the du’aa’ is delayed, this may prompt the 
    person to check on himself and examine how he stands before his Lord, so 
    that he will take stock of himself and repent; if the answer to his prayer 
    came sooner, perhaps he would become heedless and think that he was doing 
    fine, then he would develop a sense of self-admiration that may lead to his 
    doom. 

    Delay or withholding of a response may be because Allaah 
    wants to delay the reward for him until the Day of Resurrection, or Allaah 
    wants to divert an equivalent evil from him, but he does not realize that. 

    Whatever the case, the fruits of du’aa’ are guaranteed, even 
    if you do not see the response with your own eyes. So think well of your 
    Lord and say: Perhaps He has answered me in a way that I do not know. It is 
    narrated in a saheeh report that the Prophet  (peace and blessings of 
    Allaah be upon him) said: “There is no Muslim who does not offer any du’aa’ 
    in which there is no sin or severing of family ties but Allaah will give him 
    one of three things in return: either He will answer his du’aa’ sooner, or 
    he will store it up for him in the Hereafter, or He will divert an 
    equivalent evil away from him because of it.” They said: “We will say a lot 
    of du’aa’.” He said: “Allaah is more generous.” Narrated by Ahmad, 10749. 
    al-Albaani said in Saheeh al-Targheeb wa’l-Tarheeb: it is hasan 
    saheeh. 

    In conclusion, there are many reasons why a du’aa’ may not be 
    answered or the answer may be delayed; we must ponder this and not stop 
    making du’aa’, for du’aa’ will always be of benefit. 

    And Allaah knows best.