Allah is Severe in punishment
Question

One of my friends listens to music. When he is given advice, he responds by saying that Allah is Forgiving and Most merciful, but I tell him that Allah is Severe in punishment. I would like some evidence from the Sunnah and Quran that Allah is Severe in punishment.
Praise be to Allah.The questioner is to be appreciated for his keenness to guide his friend. Friends should be keen to advise and guide their brothers, without worrying about their reaction or getting tired. Allah says (interpretation of the meaning): 
“The believers, men and women, are Awliyaa’ (helpers, supporters, friends, protectors) of one another; they enjoin (on the people) Al-Ma‘roof (i.e. Islamic Monotheism and all that Islam orders one to do), and forbid (people) from Al-Munkar (i.e. polytheism and disbelief of all kinds, and all that Islam has forbidden); they perform As-Salaah (Iqaamat-as-Salaah), and give the Zakaah, and obey Allah and His Messenger. Allah will have His Mercy on them. Surely, Allah is All-Mighty, All-Wise”
[al-Tawbah 9:71]
Secondly: the majority of scholars are of the view that music is haraam, as is indicated by a great deal of evidence from the Quran and Sunnah. This was narrated from Ibn ‘Abbaas, Ibn Mas’ood, al-Shu’bi, al-Thawri and other scholars. 
See Sunan al-Bayhaqi, 10/223; al-Muhalla, 9/59; al-Mughni, 14/160 
See also question no.  5000 
Thirdly: there are many verses and hadeeths which speak of the severity of Allah’s punishment. These texts may be divided into two categories: 
1 – Those which deal directly with music 
2 – Those which speak of the severity of Allah’s punishment in general 
With regard to the first category, a number of hadeeths have been narrated concerning this. 
It was narrated that Anas ibn Maalik (may Allah be pleased with him) said: The Messenger of Allah (peace and blessings of Allah be upon him) said: “Two sounds are cursed in this world and the Hereafter: flutes (musical instruments) at times of joy and wailing at times of sorrow.” Narrated by al-Bazzaar and al-Diya’ al-Maqdisi in al-Ahaadeeth al-Mukhtaarah; classed as saheeh by al-Albaani in Tahreem Alaat al-Tarb, p. 51. 
Being cursed means being cast out far from the mercy of Allah. 
Al-Tirmidhi narrated (2138) from ‘Imraan ibn Husayn that the Messenger of Allah (peace and blessings of Allah be upon him) said: “Among this ummah will be (people who will be) swallowed up by the earth, transformed into pigs and monkeys, and pelted with stones from above.” A man among the Muslims said, “O Messenger of Allah, when will that be?” He said: “When female singers and musical instruments appear, and wine is drunk.” Classed as saheeh by al-Albaani in Saheeh al-Tirmidhi. 
With regard to the second category: In the Quran Allah says (interpretation of the meaning): 
“O you who believe! Ward off yourselves and your families against a Fire (Hell) whose fuel is men and stones, over which are (appointed) angels stern (and) severe, who disobey not, (from executing) the Commands they receive from Allah, but do that which they are commanded”
[al-Tahreem 66:6] 
“The Day they will be dragged on their faces into the Fire (it will be said to them): Taste you the touch of Hell!”
[al-Qamar 54:48] 
“But if you do it not, and you can never do it, then fear the Fire (Hell) whose fuel is men and stones”
[al-Baqarah 2:24] 
“When iron collars will be rounded over their necks, and the chains, they shall be dragged along,
 
72. In the boiling water, then they will be burned in the Fire”
[Ghaafir 40:71-72] 
“and every obstinate, arrogant dictator (who refuses to believe in the Oneness of Allah) was brought to a complete loss and destruction.
16. In front of him (every obstinate, arrogant dictator) is Hell, and he will be made to drink boiling, festering water.
17. He will sip it unwillingly, and he will find a great difficulty to swallow it down his throat, and death will come to him from every side, yet he will not die and in front of him, will be a great torment”
[Ibraaheem 14:15-17] 
“Verily, the tree of Zaqqoom
44. Will be the food of the sinners.
45. Like boiling oil, it will boil in the bellies,
46. Like the boiling of scalding water.
47. (It will be said:) Seize him and drag him into the midst of blazing Fire,
48. Then pour over his head the torment of boiling water.
49. Taste you (this)! Verily, you were (pretending to be) the mighty, the generous!”
[al-Dukhaan 44:43-49] 
“then as for those who disbelieved, garments of fire will be cut out for them, boiling water will be poured down over their heads.
20. With it will melt (or vanish away) what is within their bellies, as well as (their) skins.
21. And for them are hooked rods of iron (to punish them).
22. Every time they seek to get away therefrom, from anguish, they will be driven back therein, and (it will be) said to them: Taste the torment of burning!”
[al-Hajj 22:19-22] 
In the Sunnah, the Prophet (peace and blessings of Allah be upon him) said: “Hell will be brought on the Day of Resurrection with seventy thousand reins, each of which will be held by seventy thousand angels, dragging it along.” Narrated by Muslim, 2842. 
And he said: “This fire of yours which is lit by the sons of Adam is one seventieth part of the fire of Hell.” They said: “By Allah, if it was like this that would be sufficient.” He said: “It is sixty-nine times worse than that, each time as hot as this (worldly fire).” Narrated by al-Bukhaari, 3265; Muslim, 2843. 
And he said: “Allah has promised that whoever drinks intoxicants, He will give him to drink of the mud of khabaal.” They said: “O Messenger of Allah, what is the mud of khabaal?” He said: “The sweat of the people of Hell” or “The juices of the people of Hell.” Narrated by Muslim, 2002. 
And he said: “If a drop of Zaqqoom were to fall in this world, it would destroy the livelihood of the people of this world, so how about the one whose food it is?” Narrated by al-Tirmidhi, 2585; classed as saheeh by al-Albaani in Saheeh al-Jaami’, 5126. 
And he said: “The most lightly punished person in Hell will have two sandals and laces of fire because of which his brains will boil like a cauldron. He will not think that anyone else is more severely punished than him, but he will be the most lightly punished.” Narrated by al-Bukhaari, 6562; Muslim, 213. 
And he said: “The man from among the people of Hell who lived the most luxurious life in this world will be brought and dipped in the Fire, then it will be said to him, ‘O son of Adam, have you ever seen anything good, have you ever enjoyed any pleasure?’ and he will say, ‘No, by Allah, O Lord.’” Narrated by Muslim, 2707. 
And he said: “If there were in this mosque one hundred thousand or more, and there was among them a man from the people of Hell and he breathed out and his breath touched them, the mosque and everyone in it would be burned.” Narrated by al-Bazzaar; classed a saheeh by al-Albaani in Saheeh al-Targheeb, 3668. 
Ibn al-Qayyim said in al-Jawaab al-Kaafi, p. 53-68: 
Many ignorant people rely on the mercy of Allah and His forgiveness and kindness, and they ignore His commands and prohibitions, and forget that He is severe in punishment and He does not ward off His wrath from evildoers. Whoever relies on His forgiveness whilst persisting in sin is like one who is stubborn.  
One of the scholars said: If Allah has decreed that the hand is to be cut off  for stealing three dirhams, then do not feel safe from His punishment in the Hereafter.  
It was said to al-Hasan: “We see that you weep a great deal.” He said: “I am afraid lest Allah throws me in the Fire and does not care about me.”  
And he used to say: “Some people indulged in wishful thinking about forgiveness until they departed this world without having repented, and they would say: ‘I think positively of my Lord,’ but he was lying. If he had thought positively about his Lord, he would have done good deeds. 
Then he mentioned some of the hadeeths which speak of the severity of Allah’s punishment, then he said: 
There are far more hadeeths on this subject than we can mention. The one who is sincere should not ignore them and give himself free rein to commit sin and depend on his hope and positive thoughts about Allah.”.