In the name of Allah al-Rahman al-Rahim
Before we dwell into the answer, it will be worthwhile to note some important points:
1. Any ability to help anyone else is solely given by Allah Almighty. No one can help, or do anything in general, without the consent and the Will of Allah.
2. One is allowed to seek the help of the pious [the Prophets and the Awliya] during and even after their lifetime. This is not shirk (polytheism)
3. The Prophets and the great Awliya have been granted the permission to display ‘super-natural’ events known as Mujizah or Karamat respectively. For example, listening to many people at same time, going to many different places at one time etc. This ability and power is not taken away even after their demise, as we will see later on.
4. We can never make any judgments [Qiyas] of the life hereafter with this worldly life. The life hereafter is much better and stronger than the life of this world.
5. From the above point, we shall discover that the pious have always shown the ability to present themselves at many places. If this is possible during their lifetime, then what can we say about their powers and abilities once they leave this mundane world?
Now, we shall, through critical analysis and strong evidences, prove that the Prophets and the Awliya have the ability to assist and listen to the calls of many at one time.
Firstly, we shall prove if it’s permissible to seek help from the friends of Allah after their passing away.
Secondly, we shall prove if they can listen and assist from far.
Thirdly, we shall see if they can see and hear many calls and visit many places at the same time.
Let us mention the quote of the great Gnostic, Imam Muhammad Ibn Muhammad Ghazali [d.505AH] “One can seek help from those deceased whose help was sought when they were alive.”
In addition, it is in Bukhari and Muslim that Musa ‘Álayhi’s salam helped the Ummah of the Prophet sallAllahu álayhi wa sallam by reducing the number of daily prayers when the Prophet sallAllahu álayhi wa sallam when he embarked upon the journey of Isra’ and Mi’raj.
[Bukhari and Muslim, Chapter of Mi’raj]
The Prophet sallAllahu álayhi wa sallam has said, “There is not a single Muslim to whom I am not close to him in this world and the Hereafter. If you like, read the verse, ‘This Prophet is the owner of the Muslims even more than their own selves.’ Thus if he dies and leaves some heritage then it is for his kin. If he dies and he has unpaid dues or leave his children without any wealth then he should seek my protection as I am his Mowla (guardian).”
(Bukhara, Muslim and Tirmidhi narrated from Abu Hurairah RadiAllahu ‘Anhu. Abu Da’ud and Tirmidhi narrate from Jabir Ibn Abdullah RadiAllahu ‘Anhu). 
There are numerous other Ahadith to prove the permissibility of seeking help from those who have left this world. For example, when the companions went to the Prophet’s (sallAllahu álayhi wa sallam) grave at the time of drought and asked for his help. 
But I shall now narrate from some of those books which are read by the critics too.
Hadrat Shah ‘Abd al-Haq writes in Ham`at, under the discussion of the Nisbat [connection] to Owaysiyyah [spiritual exercise]…
“…as a result of this connection, one will see them (Awliya) in his dreams and at the time of difficulties, this group of Awliya will come and remove his difficulties.”
Also it is in Malfuzat Mazhar Jan-e-Jana…
“…I have a special relationship with Sayyiduna ‘Ali KarramAllahu Wajhahu. Whenever I am afflicted with some temporal illness I turn my attention towards Sayyiduna ‘Ali which results in my cure.”
“Sayyiduna Shaykh ‘Abd al-Qadir al-Jilani radiyAllahu ánhu pays particular attention towards his disciples. There is not a single Murid, disciple, on whom al-Shaykh Ghawth al-Thaqalayn does not pay his attention to.”
Look at the words of these statements, particularly the word ‘Ghawth Al-Thaqalain.’ Doesn’t this word mean ‘the helper of Mankind and Jinn’?
Shaykh Shah ‘Abd al-‘Aziz, discussing about the state of the souls of Awliya, writes in his Tafsir (‘Azizi):
“The Awliya of Allah, interact with this Dunya (world), even after their death, and they eliminate difficulties and help the needy. Those in grief and seek their help, are successful in reaching their objectives.” .
… “Similarly Hadrat Khawaja Naqashband pays attention towards his beloveds. The shepherds and the travellers hand over their animals and wealth in protection of Hadrat Khawaja Naqshband whenever they want to go to sleep or if they want to go through the deserts, seeking his unseen help.”
The student of Hadrat Qadi Thanaullah Pani Pati, and the disciple of the aforementioned Mirza Sahib, writes in, Tadhkirat al-Mowta, discussing about the souls of the Awliya of Allah:
“Their souls go to the heavens, to the earth and to the gardens of Jannah. They help their beloveds and friends in this world and in the hereafter, and defeat the enemies.”
It is mentioned in the same Jawahir Khamsa, “One should read Nadi ‘Ali seven, three times or once daily. The words are, “Nadi ‘Aliyyan Math’haral ‘Aja’ib, Tajidhu ‘Awnan Laka fi al-Nawahib, Kullu Hammin wa Ghammin Sayanjali, Biwilyatika Ya ‘Ali Ya ‘Ali Ya ‘Ali”. (“Call ‘Ali (radiyAllahu ánhu), the one who shows wonders, you will find him your protector at the time of calamities. All the calamities fade away due to your Sainthood O ‘Ali! O ‘Ali! O ‘Ali!).
Don’t you see this! Hadrat ‘Ali has passed away some thousands of years ago yet this great scholar is teaching us to seek his help…SubhanAllah!
The Prophet sallAllahu álayhi wa sallam has said, “My daughter Fatimah is the Hur among the people. She doesn’t go through what other women have to go through (menstruation and other impurities). Allah named her Fatimah as He will protect her and anyone who loves her from the fire of Hell.” (Khatib narrates from Ibn ‘Abbas radiyAllahu ánhu). 
So even in this day and age, if someone loves the beloved of the beloved of Allah, Fatimah radiyAllahu ánha then he will be protected from the punishment of Allah. What greater calamity can there be than the punishments of the Hereafter? If this is the blessing about loving her then what is going to be her status!
Amir al-Mu’minin, Sayyiduna ‘Umar radiyAllahu ánhu once saw his wife, Umm Kulthum (the daughter of ‘Ali radiyAllahu ánhu) crying. He asked the reason of her crying. She replied, “This Jew (she meant Hadrat Ka’ab al-Ahbar radiyAllahu ánhu: one of the greatest of the Tabi’in and accepted Islam during the era of Sayyiduna ‘Umar) is saying that you are one of the doors of the Hell.” Sayyiduna ‘Umar radiyAllahu ánhu said, “What Allah wills! I have a great hope that Allah will make me Sa`id (happy)” and then he called for Hadrat Ka’ab. When he arrived he asked him about the statement. Hadrat Ka’ab replied, “Don’t hasten! I swear by He in whose hands my life lies, the month of Dhu al-Hijjah will not yet be completed that you will enter the paradise.” Hadrat ‘Umar asked, “What is all this? Paradise and Hellfire?” He replied, “I swear by He who has the control of my life, I see you one of the doors of Hell in the Book of Allah; stopping people from falling into the hellfire. When you will pass away the people will begin falling into it till the Day of Judgement.” (Ibn Sa’ad in his Tabaqat and Abu al-Qasim Ibn Bashran narrate from al-Jari the slave of Sayyiduna ‘Umar radiyAllahu ánhu). 
Look at this Hadith! If someone can have a connection to the other world living on this earth then how come the people of the ‘other-world’ have no connection to this world?!
Remember! As mentioned earlier, when the pious die, their ability to help others does not diminish or disappear. They are alive in their grave [which is yet another broad topic] and their souls become stronger. We will come to this point later.
There is a very well-known Hadith when Sayyiduna ‘Umar radiyAllahu ánhu was on his pulpit when he called out “O Sariah! Go towards the mountain”. He was calling Hadrat Sariah who was in the midst of a battle some hundreds of miles away. Sayyiduna ‘Umar radiyAllahu ánhu saw it in Madina Munawwarah and Hadrat Sariah heard his call…SubhanAllah
[Tarikh Ibn Kathir, Khilafat ‘Umar radiyAllahu ánhu]
The Prophet sallAllahu álayhi wa sallam has said, “If you lose something and you are in such a place where you don’t find anyone to help then one should say, ‘O the Servants of Allah! Help Me! O The Servants of Allah! Help Me! O The Servants of Allah! Help Me!’ Since there are some servants of Allah present there whom you do not see.” [Tabrani narrated from ‘Utbah Ibn Garwan radiyAllahu ánhu]. 
The Messenger of Allah sallAllahu álayhi wa sallam has said, “If you lose your animal then you should say, ‘O Servants of Allah, take hold of it!’ ” [Ibn al-Sani narrates from Ibn Mas’ud radiyAllahu ánhu]. 
The Prophet of Allah sallAllahu álayhi wa sallam has said, “He should say, ‘Help me O Servants of Allah!’ ” [Ibn Abi Shaybah and Bazzar narrate from Ibn ‘Abbas radiyAllahu ánhuma] 
These three Ahadith which have been narrated by the three blessed companions of the Prophet sallAllahu álayhi wa sallam are well used and practiced.
Imam Ahmad Rida Khan radiyAllahu ánhu has written more upon this topic on one of his treatise, Anhar al-Anwar Man Yammu Salat al-Asrar (1305 A.H.),  highlighting the secrets of the prayer Salat Al-Ghawthiyyah and about the eleven steps taken towards Baghdad Sharif.
In the book, Qawl al-Jamil, it has mentioned the method of picturing one’s Shaykh [spiritual guide], which is one of the Sufi practices of Naqshbandiyya Tariqah:
“When the Shaykh is not present then one should picture him with love and respect. The picture will give all the benefits which the presence of a Shaykh gives a person.” 
Quoting from Shah ‘Abd al-‘Aziz, it is written in Shifa al-‘Alil, “It is true that this is the most effective way.” 
This should be enough to convince those who are sincerely seeking the truth. If more details needed read Imam Ahmad Rida’s renowned book, Al-Amnu Wa al-‘Ula which will In sha Allah eliminate many doubts from the heart.
The Great Gnostic and Scholar Shaykh Imam ‘Abd al-Wahhab al-Sha’rani ‘Álayhi al-Rahmah writes in Kitab al-Jawahir wa al-Durar [p.165]:
“…Our Master Ibrahim al-Disouqi radiyAllahu ánhu gave a sermon and led the Jumu’ah [Friday] prayer in fifty different places. Similarly, our Master Muhammad al-Khadari radiyAllahu ánhu led the Friday prayer in different parts of Surus [name of a city] at one time.
“One of the miracles [Karamat] of our Master ‘Abd al-Qadir al-Shatuti radiyAllahu ánhu [not to be confused with Shaykh ‘Abd al-Qadir al-Jilani radiyAllahu ánhu] was that he spent a night at his disciple’s house on a small island in front of the Egyptian park named Rawdat al-Miqyas. In the same night, he stayed over at someone else’s house in another city. Both hosts gave him milk to drink and stayed with him.
“Meanwhile, there was another group of people who narrated that king Qatba’i before leaving to travel to Aleppo [Humus, Syria] King Qatba’i sought permission from ‘Abd al-Qadir al-Shatuti radiyAllahu ánhu. He reached Aleppo where he found the Shaykh lying on a bed with a deteriorating health. The people said to the king that the Shaykh has been in this state for the last one year; whereas the king met him a month ago in Egypt in a very healthy state.
“I asked my teacher, Shaykh ‘Ali Khawwas radiyAllahu ánhu: If the ‘copied’ bodies [in other words, if a saint can go to many places at once, the other bodies are copied or Mithali in Arabic] of a Wali commits an offence then which body will be liable? He replied, ‘The copied bodies, though they may be in thousands, they are liable and they will also gain reward (if they do good).’
“I then asked, ‘How can one soul have the connection with all this bodies and how can it be responsible for the actions of all these bodies? He replied saying, ‘like one soul controls all the parts of a body, similarly it controls all the different bodies. If the different body parts commit an offence, the soul will be questionable, similarly is the state when the different bodies undertake an action; all the actions are controlled by this one soul.” [After asking another question], “They can do this because they have attained the secret of the word KUN [‘Be’] and this is through the miracle bestowed to them. This will be the state of the people of paradise.’ ”
So from the above account we get to perceive the friends of Allah have the capability to roam around many places, and undertake many different actions at one single time. If this is the state of the Awliya, then how can we imagine the status of the Prophet sallAllahu álayhi wa sallam?
Moreover, Mulla ‘Ali Qari ‘Alayhi al-Rahmah states, “The friends of Allah can be in several places at one moment and can even have few likenesses of body simultaneously.” 
Imam Ibn al-Haj and Imam Qastalani ‘Alayhi al-Rahmah state, “Our Scholars have stated that that there is no difference between the life and the demise of the Prophet sallAllahu álayhi wa sallam . He sees his Ummah, their actions, knows their feeling and intentions.”
So much can be written on this topic, but I will just finish off this point with one narration and see the power of the enemy of Allah, not a friend!
Hafidh Ibn Kathir writes the Tafsir (under the verse 27 of Surah al-A’araf), “Apart from his servants, Allah has given power to Shaytan, who sits on his throne in the sea and sees you wherever you may be.”
From all the above quotations, it is evident that the Awliya can be at many places in one time, let alone hearing and seeing from one place!
Now from the above three points we can deduce the following
- The help of Awliya can be sought, even after their death.
- They can help even after their death.
- Their souls become even stronger after their death.
- They can perform miracles even after death.
- They can be present at many places at one time, through the miracle bestowed to them by Allah.
Thus we can conclude that the can also be present in many places, and help many at one time, even after their death through the miracles which Allah has granted them. They also have the ability to help whom they want and listen to the calls of many at the same time. All this is through the permission granted to them by Allah the Almighty.
It is hoped that this would suffice the seekers of truth…In Sha Allah.
[N.B. for more information on the topic please refer to the book Obliteration of Falsehood (translation of Ja’a al-Haqq).]
Allah knows best.
Answered by Mawlana Mohamed Husein Qadri
 Sahih al-Bukhari, the book on al-Istiqrad, the chapter on al-Salat ‘Ala man Taraka Daynan, (Qadimi Kutub Khana, Karachi), vol. 1, p. 323. Also the book on al-Tafsir, Surah al-Ahzab, vol. 2, p. 705.
Sahih Muslim, the book on al-Fara’id, the chapter on Ada’i al-Dayn Qabla al-Wasiyyah, (Qadimi Kutub Khana, Karachi) vol. 1, p. 36.
Sunan of Abu Da’ud, the book on al-Imarah, the chapter Fi Arzaq al-Dhuriyyah, (Aftaab ‘Aalam press, Lahore), vol. 2, p. 54.
Musnad Ahmad Ibn Hanbal, narrated from Abu Hurayrah radiyAllahu ánhu, (Al-Maktab al-Islami, Beirut), vol. 2, pp. 334-335.
Sharh al-Sunnah, the book on al-Fara’id, Hadith # 2241, (Al-Maktab al-Islami, Beirut), vol. 8, p. 324.
Sunan al-Kubra Li al-Baihaqi, the chapter on al-Asabah, (Dar Saadir, Beirut), vol. 6, p. 238 and vol. 7, p. 58.
 See Ibn Taymiya’s Iqtisa Sirat al-Mustaqim, p. 373 and Fath al-Bari, chapter on Istisqa.
 Ham’at, Ham’a 11, (al-Shah Waliyullah al-Dahlavi Academic, Hyderabad, Pakistan), p. 59.
Kalimat Tayyibat, Malfuzat Mazhar Jan Jana, (Mujtaba’i press, Delhi), p. 78.
 Ibid. p. 83.
 Tafseer Fath al-‘Azizi, under the verse 84:18, (Muslim Book Depot, Laal Kunwa, Dehli), p.206.
 Ibid. p. 83.
 Tadhkirat al-Mowta, (Mujtba’i press, Delhi), p. 41.
 Urdu Translation of Jawajir Khamsa, Muhammad Baygh Naqshbandi, (Dar al-Isha’at, Karachi), p. 282 and 453.
 Tarikh Baghdad, the biography of Ganim Ibn Hamid 6772, (Dar al-Kitaab al-‘arabi, Beirut), vol. 12, p. 331.
Kanz al-‘Ummal, narrated from Ibn ‘Abbas radiyAllahu ánhu, Hadith# 34226, (Muassas al-Risala, Beirut), vol. 12, p. 109.
 Al-Tabaqat al-Kubra Li Ibn Abi Sa’ad, the mentioning of Istikhlaf ‘Umar radiyAllahu ánhu, (Dar saadir, Beirut), vol. 3, p. 332.
Kanz al-‘Ummal, with reference to Ibn Abi Sa’ad and Abu al-Qasim Ibn Bashran, Hadith# 35787, (Muassas al-Risala, Beirut), vol. 12, pp. 570-571.
 Al-Mu’jam al-Kabir, narrated from ‘Ataba Ibn Ghazwan, Hadith# 290, (Al-Maktabat al-Faisaliyya, Beirut), vol. 17, pp. 117-118.
 ‘Amal al-Yawm wa al-Laylah, Hadith# 208, (Dairat al-Ma’arif al-‘Uthmaniyya, Hyderabad), p. 136.
 Al-Musannaf li Ibn Abi Shaybah, the book on al-Du’a, Hadith# 29711, (Dar al-Kutub al-‘Ilimiyya, Beirut), vol. 6, p. 92.
Al-Bahr al-Zakhkhar, Hadith# 4922, vol. 11, p. 181 and al-Mu’jam al-Kabir, Hadith# 290, vol. 17, p. 118.
Kashf al-Astar ‘An Zawa’id al-Bazzar, the book on al-Adhkar, Hadith# 3128, (Muassas al-Risala, Beirut), vol. 4, p. 34.
 This book is printed in the seventh volume of Fatawa-e-Razawiyyah (Raza Foundation, Jami’ah Nizamiyya Razawiyya, Lahore), p. 569.
 Al-Qawl al-Jamil, sixth chapter, (H.M.Saeed Company, Karachi), pp. 81-82.
 Shifa al-‘Alil Ma’a al-Qawl al-Jamil, (H.M. Saeed Company, Karachi), p. 80.
 Mirqat, the chapter of Ma Yuqalu ‘Inda Man Hadar al-Mowt.
 Madkhal, Mawahib al-Ladunniyyah, v.2, p. 387.
 Tafsir Ibn Kathir, Surah al-A’araf, verse 27.