1. Belief in death

Introduction
Belief in the Last Day implies belief in death, which leads a person to the hereafter and is the individual “hour” for each person.

1.1. The inevitability of death for all living beings in this world
Allah, may He be Glorified and Exalted, says (interpretation of the meaning), "All will perish but His Countenance. His is the judgement and to Him you will be brought back." (al-Qasas 28:88) "All that is on earth will perish, but the Countenance of your Lord will abide forever, in all its majesty and munificence." (al-Rahman 55:26-27) "Every soul will taste death." (Al ‘Imran 3:185)

Ibn Rajab said, “Allah, may He be Glorified and Exalted, has decreed death for His slaves, as He Allah, may He be Glorified and Exalted, says: Every soul will taste death Al ‘Imran 3:185. Death is the departure of the soul from the body, and that only happens with immense pain, which is the greatest pain that a person could suffer in this world.”

1.2. Belief that lifespans are preordained

Every creature has a preordained lifespan that it will reach. Allah, may He be Glorified and Exalted, knew all that and His pen wrote that by His command. Then the angel wrote it for each individual when he was in his mother’s womb. No one’s lifespan will increase or decrease, and it cannot be changed or altered from what Allah, may He be Glorified and Exalted, knew from eternity and what He willed and decreed.

Allah, may He be Glorified and Exalted, says (interpretation of the meaning), "No soul can die except by Allah’s leave, and at an appointed time." (Al ‘Imran 3:145)

Ibn ‘Uthaymin said regarding the verse (interpretation of the meaning) "When their appointed time comes, they will not be able to delay it for a single moment or bring it forward." (Yunus 10:49), “When a person’s appointed time comes, it cannot be delayed even by one minute, and it cannot be brought forward; rather it is counted and defined, and cannot be brought forward or put back, so why hope to live a long life?”

1.3. Belief that no one knows where he will die except Allah alone
It is obligatory to believe that this inevitable time for the end of every lifespan is something of which no one has any knowledge of where it will happen, because it is one of the keys of the unseen, knowledge of which Allah, may He be Glorified and Exalted, has withheld from all of His creation, so no one knows it except Him Allah, may He be Glorified and Exalted. Allah, may He be Glorified and Exalted, says (interpretation of the meaning), "With Him are the keys of the unseen; no one knows them but He." (al-An‘am 6:59) ‘Abdullah ibn ‘Umar (may Allah be pleased with him) narrated that the Messenger of Allah (blessings and peace of Allah be upon him) said, "The keys of the unseen are five: Verily, Allah alone has knowledge of the Hour; it is He Who sends down rain and He knows what every womb contains. No soul knows what it will do tomorrow, and no soul knows in what land it will die. Verily, Allah is All-Knowing, All-Aware." (Luqman 31:34) (Al-Bukhari)

Ibn ‘Uthaymin said, “No one knows in what land he will die; will he die in his own land or in a distant land or in a land close to his own? Or will he die at sea or in the air? No one knows that except Allah.

If you do not know in which land you will die, and you are able to go in any direction you want, by the same token you do not know when you will die, and you do not know at what time you will die; will you die in the morning or the evening, at night or in the middle of the day? You do not know. Will you die in a month that is close at hand or in a month that is further off? You do not know. You do not know when you will die or in which land you will die.

As you are like that, then you should assume that your time is short and do not hope to live long, for no one knows when he will die and he does not know in which land he will die.”

1.4. This world is a transient realm whereas the hereafter is the eternal abode

‘Abdullah ibn ‘Umar (may Allah be pleased with him) narrated, "The Messenger of Allah (blessings and peace of Allah be upon him) took hold of my shoulder and said, 'Be in this world as if you are a stranger or a traveller.'" And Ibn ‘Umar (may Allah be pleased with him) used to say, "When evening comes, do not expect to live until morning, and when morning comes, do not expect to live until evening. Make the most of your good health before you fall sick and make the most of your life before you die." (Al-Bukhari).

Ibn Rajab said, “This hadith clearly states that the individual should assume that his stay in this world will be short, and that the believer should not regard this world as his home and feel too comfortable in it. Rather his attitude in it should be as if he is about to set out on a journey, so he should be preparing himself to set out. All the prophets and their followers offered this advice. Allah, may He be Glorified and Exalted, tells us that the believer among the family of Pharaoh said (interpretation of the meaning), 'O my people, the life of this world is but a brief enjoyment, whereas it is the hereafter that is the permanent abode.'" (Ghafir 40:39) And the Prophet (blessings and peace of Allah be upon him) used to say, 'What I have to do with this world? The likeness of me and this world is that of a rider who naps beneath the shade of a tree, then he continues on his way and leaves it behind.'" (Al-Tirmidhi, Ibn Majah, Ahmad. Sahih)

1.5. Preparing for death before it comes

Death is the dividing line between this realm and the hereafter; it is what separates the time of striving and the time of requital, the time for provision sending ahead and the time for going to collect it. After death, no one can have any excuse, no way to increase good deeds and no way to decrease bad deeds. After death, you are helpless and cannot ransom yourself; there will be no kind of money and no place to settle or stay except the grave, which is either one of the gardens of Paradise or one of the ditches of Hell, where you will remain until the Day of Resurrection and requital.

Allah, may He be Glorified and Exalted, says (interpretation of the meaning), "Until, when death comes to one of them, he says: My Lord, send me back, so that I may do the righteous deeds that I have failed to do. Nay, it is but a word he says. And behind them is a barrier, until the day they are resurrected." (al-Mu’minun 23:99-100)

Ibn Kathir said, “Here Allah, may He be Glorified and Exalted, tells us about the dying person at the moment of death, if he was one of the disbelievers or one of those who were heedless of His command. He tells us what he says at that moment, and how he asks to go back to this world in order to rectify what he did wrong during his lifetime.”

And Allah, may He be Glorified and Exalted, says (interpretation of the meaning), "O you who believe, fear Allah, and let every soul consider what it has sent forth for tomorrow." (al-Hashr 59:18)

Ibn Jarir said, “The words and let every soul consider what it has sent forth for tomorrow mean: Let one of you think of what he has sent on ahead of deeds for the Day of Resurrection: are they righteous deeds that will save him or are they bad deeds that will doom him?”

And Allah, may He be Glorified and Exalted, says (interpretation of the meaning), "O you who believe, do not let your wealth and your children distract you from the remembrance of Allah. Whoever does that, it is they who are the losers. And spend from that which We have provided for you, before death comes to one of you and he says: My Lord, if only You would grant me a reprieve for a little while, then I would give in charity and be among the righteous. But Allah will not grant a reprieve to any soul when its appointed time has come, and Allah is well aware of all that you do." (al-Munafiqun 63:9-11)

Ibn Rajab said, “What the individual must do is prepare for death before it comes, by doing righteous deeds and hastening to do them, for he does not know when this calamity will befall him, by night or by day… So whoever obeys Allah, fears Him and adheres to His limits during his lifetime, Allah will take care of him at the moment of his death; He will cause him to die as a believer and He will make him steadfast with the word that stands firm in the grave, when he is questioned by the two angels; He will ward off from him the torment of the grave and will comfort him when he is alone in the darkness.”