He wants to enter Islam but he cannot give up coffee when fasting!
Question

                I am a woman and I have a friend who wants to embrace Islam, but when he found out that he would have to fast, and that when fasting he would have to avoid eating and drinking, he backed off, because he is addicted to coffee and he drinks it all the time, because he suffers from migraines and headaches, and it is like a remedy for him. How can I help him? Do you have any suggestions?.
Praise be to Allah.
      Firstly: 

    The greatest of blessings that Allah bestows upon His slave, 
    which is also a sign of his being blessed and his success, is that his Lord 
    guides him to His religion, and opens his heart to believe in Him and submit 
    to Him. Allah says (interpretation of the meaning):

    “And whomsoever Allaah wills to guide, He opens his breast 
    to Islam; and whomsoever He wills to send astray, He makes his breast closed 
    and constricted, as if he is climbing up to the sky. Thus Allaah puts the 
    wrath on those who believe not”

    [al-An‘aam 6:125]. 

    Shaykh al-Sa‘di (may Allah have mercy on him) said: 

    Here Allah says, describing to His slaves the sign of a 
    person's being blessed and guided, and the sign of his being doomed and 
    misguided, that for the one whose heart is open to Islam and is filled with 
    the light of faith and certainty, that he feels at ease with it, so he loves 
    to do good and finds it easy to do it. This is a sign that Allah has guided 
    him and blessed him by enabling him to follow the straight path. 

    The sign of the one whom Allah wills to send astray is that 
    his heart becomes constricted and closed, so it rejects faith, knowledge and 
    certainty, and his heart is filled with specious arguments and whims and 
    desires. So nothing reaches him, and his heart is not open to doing good 
    deeds. It is as if he is “climbing up to the sky”, i.e., as if he is asked 
    to climb up to the sky when he has no means of doing so. 

    The reason for this is their lack of faith, because of which 
    Allah “puts the wrath on them”, because they have blocked the door of mercy 
    and kindness. That is the way that does not change, because the one who 
    gives (in charity) and fears Allah, and testifies to the best, Allah will 
    indeed make smooth for him the path of bliss, but for the one who is greedy 
    miser and thinks himself self sufficient, and gives the lie to the best, 
    Allah will make smooth for him the path to misery. 

    End quote. 

    Tafseer al-Sa‘di, 272. 

    We ask Allah to guide this seeker and open his heart to 
    Islam, and to enable him to repent to Him and submit to His religion. 

    Secondly: 

    It should be noted that fasting the month of Ramadan is not 
    something to be taken lightly; rather it is one of the five pillars of Islam 
    and one of the great foundations on which this faith is built, as it says in 
    the well-known hadeeth from Ibn ‘Umar (may Allah be pleased with him) who 
    said: The Messenger of Allah (blessings and peace of Allah be upon him) 
    said: “Islam is built on five (pillars): testimony that there is no god 
    except Allaah and that Muhammad is His slave and Messenger, establishing 
    regular prayer, paying zakaah, pilgrimage to the House and fasting Ramadaan.” 

    Narrated by al-Bukhaari (8) and Muslim (16). 

    It should also be noted that uttering the twin declaration of 
    faith (al-shahaadatayn) and entering Islam means that the person submits 
    with his heart and physical faculties to the Lord of the Worlds, and that he 
    believes in Him and in what came from Him; he submits to his Lord and 
    accepts His rulings, commands and prohibitions, and he believes what He 
    tells us of stories. Allah says (interpretation of the meaning):

    “We sent no Messenger, but to be obeyed by Allaah’s Leave. 
    If they (hypocrites), when they had been unjust to themselves, had come to 
    you (Muhammad صلى الله عليه وسلم) and 
    begged Allaah’s forgiveness, and the Messenger had begged forgiveness for 
    them, indeed, they would have found Allaah All-Forgiving (One Who forgives 
    and accepts repentance), Most Merciful.

    65. But no, by your Lord, they can have no Faith, until 
    they make you (O Muhammad صلى الله عليه وسلم) 
    judge in all disputes between them, and find in themselves no resistance 
    against your decisions, and accept (them) with full submission”

    [al-Nisa’ 4:64-65]. 

    Ibn Katheer (may Allah have mercy on him) said: 

    In the words “But no, by your Lord, they can have no 
    Faith, until they make you (O Muhammad صلى الله 
    عليه وسلم) judge in all disputes between them”, Allah is swearing 
    by His holy Self that no one believes until he makes the Messenger 
    (blessings and peace of Allah be upon him) judge in all his affairs. So 
    whatever he rules is the truth to which he must submit both inwardly and 
    outwardly. Hence He says “and find in themselves no resistance against 
    your decisions, and accept (them) with full submission” i.e., if they 
    appoint you as judge, they should obey you in their hearts and not find any 
    resistance in themselves against your decision and submit to it both 
    outwardly and inwardly. Thus they should submit completely, without any 
    resentment or dispute.

    End quote. 

    Tafseer Ibn Katheer (2/349) 

    There are very many verses in the Holy Qur’aan which confirm 
    this principle and explain it. 

    Thirdly: 

    Once we have understood this important principle of faith, 
    which is submission to and acceptance of everything that comes from Allah, 
    may He be exalted, and submitting to Him both inwardly and outwardly, then 
    we will also understand that fasting Ramadan is an important pillar of 
    faith, and no person’s faith is valid unless he accepts it. So what we have 
    to do, when calling this seeker to the religion of Allah, is explain to him 
    that there is no problem that would prevent him from entering Islam; Allah 
    does not put any hardship upon His slaves in their religion; rather He makes 
    it easy for them and relieves them of what that may cause them of hardship 
    and difficulty . 

    Is this man drinks coffee because of what he suffers of 
    headaches and migraines, then he can consume the sufficient amount of it 
    during the night, then when he begins to fast during the day, he should stop 
    doing that until the sun sets. He can also seek help by using the medication 
    that will help him with his headache or reduce its effects. 

    But it is well known that if a sick person is affected by his 
    sickness during the day, and his sickness will be affected by fasting, then 
    it is well known that such individuals are exempted in the religion of 
    Allah. So if he gets a headache and needs to take medicine, and cannot fast 
    that day, he can break the fast for that day, then when the month has ended 
    he should make up the days that he did not fast because of the excuse of 
    being sick. As Allah says (interpretation of the meaning):

    “O you who believe! Observing As-Sawm (the fasting) is 
    prescribed for you as it was prescribed for those before you, that you may 
    become Al-Muttaqoon (the pious).

    184. [Observing Sawm (fasts)] for a fixed number of days, 
    but if any of you is ill or on a journey, the same number (should be made 
    up) from other days. And as for those who can fast with difficulty, (e.g. an 
    old man), they have (a choice either to fast or) to feed a Miskeen (poor 
    person) (for every day). But whoever does good of his own accord, it is 
    better for him. And that you fast is better for you if only you know”

    [al-Baqarah 2:183-184]. 

    But if a person wants to drink coffee because he loves it, 
    and he does not want to forsake his desire for it during the day for one 
    month of every year, then this person is not ready to believe and submit or 
    to adhere truly to any religion, whether it is Islam or any other, because 
    religion -- any religion -- requires its followers to be able to obey and 
    submit, and to give up the whims and desires of the self. This is the test 
    and it is the obstacle that many people fail to overcome, the obstacle of 
    whims and desires and going against what the nafs (self) desires. This is 
    what Allah mentioned in His Book to His Prophet, as He said (interpretation 
    of the meaning):

    “Have you (O Muhammad صلى 
    الله عليه وسلم) seen him who has taken as his ilâh (god) his own vain 
    desire? Would you then be a Wakîl (a disposer of his affairs or a watcher) 
    over him?”

    [al-Furqaan 25:43]. 

    Fourthly:  

    Allah, may He be glorified and exalted, is more compassionate 
    towards His slaves than a mother to her child. When a person turns to his 
    Lord, Allah turns to him and more so, as it says in the hadeeth narrated 
    from Abu Hurayrah (may Allah be pleased with him) who said: The Messenger of 
    Allah (blessings and peace of Allah be upon him) said: “Allah says: ‘I am as 
    My slave thinks I am, and I am with him when he remembers Me. If he 
    remembers me to himself, I remember him to Myself; if he remembers Me in a 
    gathering, I remember him in a gathering better than it; if he draws near to 
    Me a handspan, I draw near to him an arm’s length; if he draws near to me an 
    arm’s length, I draw near to him a fathom’s length; if he comes to Me 
    walking, I go to him at speed.” Narrated by al-Bukhaari (7405) and Muslim 
    (2675). 

    So be confident, O slave of Allah, that when you turn to 
    Allah sincerely, Allah will turn to you and will help you, make things easy 
    for you, open your heart, suffice you against what distresses you and 
    support you in ways you never imagined. Perhaps Allah will heal you of your 
    sickness, or perhaps He will suffice you and relieve you of that addiction 
    to what you drink [coffee]. So turn to Allah and think positively of your 
    Lord, and tell Him of your need. But the condition is that you should be 
    serious about submitting to the command of Allah and accepting what has come 
    from Him. Allah, may He be exalted, says (interpretation of the meaning):

    “As for him who gives (in charity) and keeps his duty to 
    Allaah and fears Him, 

    6. And believes in Al‑Husnaa [The Best, (i.e. either Lâ 
    ilâha illAllaah: none has the right to be worshipped but Allaah) or a reward 
    from Allaah (i.e. Allaah will compensate him for what he will spend in 
    Allaah’s way or bless him with Paradise)],

    7. We will make smooth for him the path of ease 
    (goodness).”

    [al-Layl 92:5-7]. 

    Fifthly: 

    It should be noted that if a person is sincere in his belief 
    in his Lord, then is unable to do some of the duties, or he is overwhelmed 
    by his nafs and whims and desires, and falls into sin, that is not the end 
    of the road. Rather the gate of repentance and turning to his Lord is open. 
    Moreover, he -- despite his sin -- may be forgiven by Allah and has to hope 
    that his sin and error will be pardoned. But the problem for which there is 
    no solution is if a person remains in a state of shirk (associating others 
    with Allah) and turning away from the religion of his Lord. Allah says 
    (interpretation of the meaning):

    “Verily, Allaah forgives not that partners should be set 
    up with Him (in worship), but He forgives except that (anything else) to 
    whom He wills; and whoever sets up partners with Allaah in worship, he has 
    indeed invented a tremendous sin”

    [al-Nisa’ 4:48].

    Sixthly: 

    It is very important to note that it is not acceptable for 
    there to be a relationship or friendship between a man and a woman in Islam; 
    rather this is one of the actions of jaahiliyyah (ignorance) and the Muslim 
    should be above doing that. Islam forbids free mixing of men and women, men 
    entering upon women or being alone with them. 

    This has been explained previously in numerous answers under 
    the heading “Relationships between the sexes” on this website; please refer 
    to that. 

    And Allah knows best.