The most important events that will happen on the Day of Judgement are when we will be held accountable for our deeds and when we will be questioned by our Lord Allah [az]. There are many Qur'anic verses and ahaadith [narrations] that tell us about these events so that the believers will prepare themselves for the most important, final test. They can prepare for this test with their strong faiths and with their righteous deeds. Allah (swt) says what could be translated as, "Draws near for mankind their reckoning, while they turn away in heedlessness." (Surat Al-'Anbia', Verse 1.)
Also, He says what could be translated as, "Verily, to us will be their return: -Then verily, for us will be their reckoning." (Surat Al-Ghashiah, Verses 25 and 26.)
And He says what could be translated as, "Then surely, we shall question those (people) to whom it (the book) was sent and verily, we shall question the Messengers." (Surat Al-A'raf, Verses 6 and 7.)
These verses and other ahadeeth that will be mentioned, state one of the events that will happen on the Judgement Day. What will happen on this day is called, “ Al-Hisaab ” [The Reckoning] which is when Allah (swt) will ask every person what they have done in their lives.
There will be two different ways that Allah will hold people accountable for their deeds:
The First Method: Allah will quickly and easily skim through the people's deeds, and will allow them to enter paradise safely. Those who believe strongly with sincerity, will enter paradise in this manner.
The Second Method: Allah will discuss the people's deeds in depth and in detail, and will hold them accountable for each evil act they committed. Then Allah will send them away to the Hell Fire. These are the disbelievers, hypocrites, those who are weak in their faith, or those who are not sincere will enter the Hell Fire in this manner.
Allah (swt) describes that Day in what could be translated as, "On the Day when every person will be confronted with all the good he has done, and all the evil he has done, he will wish that there were a great distance between him and his evil." (Surat Al-Imran, Verse 30.)
Anyone who is questioned in depth and in detail will surely be tortured:
Imams Bukhari and Muslim reported that Ai'sha (ra) said that the Prophet Muhammad (peace be upon him) said: "Destroyed is the one who has his account settled on the Day of Resurrection.” Ai'sha said: "O Messenger of Allah, didn't Allah say "Then he who is given his records in his right hand soon will his account be taken by easy reckoning" (Surat Al-Inshiqaq, Verses 7 and 8.) The Prophet (peace be upon him) replied: "This is the skimming through the deeds; and destroyed is the one who has his account settled on the Day of Judgment.”
The good believer will have an easy reckoning and Allah (swt) will cover up his sins after He reminds him about them. Then he will forgive him from his sins, and allow him to enter paradise.
This is concluded from a hadith reported by Imams Bukhari and Muslim in which the Prophet (peace be upon him) said: "Allah will bring the believer very close and privately and ask him "Do you know this sin? Do you know that sin? The believers reply will be, “Yes Oh Lord,” until he is reminded about all of his sins, and he thinks he will perish. Then Allah will say "I covered up your sins during your life, and I will forgive your sins today.” Then he will be given his book of good deeds. But the unbelievers and hypocrites will be asked about their deeds loudly in front of the creatures.
"These are the ones who lied against their Lord!" No doubt! The curse of Allah is on the Dhaalimoon (polytheists, wrongdoers, oppressors, etc.)!" (Surat Huud, Verse 18.)
Allah will confront His servant directly, without a mediator.
The Messenger (peace be upon him) said: “Allah will talk to everyone directly, without a translator. The person will look to his right, and will not see anything but his deeds. Then the person, will look in front of himself and will see nothing but the hellfire facing him. So protect yourself from Hellfire even by giving a charity of half a date." (Reported by Imam Bukhari.)
Prayer will be the first thing a person will be questioned about on the Day of Judgment.
Prayer is a right of Allah (swt), and people will be questioned about it. They will be asked if their prayers were done completely and with good quality. If a person performs prayers with the utmost of quality, then the person will be saved. If the prayers were done incompletely or half-heartedly, then his voluntary prayers will suffice for the shortcomings.
The Messenger (peace be upon him) told us in an authentic hadith , “The first thing the people will be accountable for on the Day of Judgment is prayer, Allah will say to His angels (even though he already knows): “Look at my servants prayers, were they complete or not?” If they were complete, it will be written as complete. If they were not fully complete Allah will say: “See if my servant has voluntary prayers, if he has them Allah will say: Complete his obligatory prayers shortage with his voluntary prayers.” Then the rest of his deeds will be dealt with in the same manner.” (Reported by Imams Ahmad, Abu Dawood, An-Nisa'i, and Al-Hakim)
We will be asked in the Day of Judgement about five things.
The Prophet Muhammad (peace be upon him) said: “The son of Adam will not pass away from Allah until he is asked about five things: how he lived his life, and how he utilized his youth, with what means did he earn his wealth, how did he spend his wealth, and what did he do with his knowledge.” (Hasan hadith reported by Imam At-Tirmithi.)
We will be asked in the Day of Judgement about all of the blessings and bounties that Allah gave us in this life. Some of these blessings may include our good health, our wealth, our food and drink, our ride and our home, etc. Allah (swt) says in the Noble Qur'an, what could be translated as, “Then, on that Day, you shall be asked about the delight (you indulged in in this world).” (Surat Al-Takathir, Verse 8.)
The Prophet (peace be upon him) described the questioning in a speech reported by Imam Muslim: "Allah (swt) will meet a person and ask him: "O person, wasn't I generous with you, and made you with a spouse, and made the horses and camels at your disposal?" The servant will reply "yes!" Allah (swt) will then ask “Did you think that you will meet me?” He will reply: "No!" Allah (swt) will say: "I will forget you like you forgot me!" Then Allah (swt) will meet another person and his reply will be the same as the first person. Then Allah (swt) will meet a third person and will ask similar questions, and the person's reply will be: "O Lord I believed in you, in your books, and in your messengers. I prayed, I fasted, and I gave charity." And he will praise Allah as much as he can. Allah (swt) will say: "Hold on to your words, Now we will bring the witnesses." The person will ask himself “Who will testify against me?” Then that persons mouth will be sealed, and his thighs, flesh and bones will be asked to speak. They will speak about his bad deeds. He will know that he has no excuse. That is the hypocrite Allah (swt) will be furious with!”
Allah (swt) describes that situation in what could be translated as, "On the day when their tongues, their hands, and their feet will bear witness against them as to their actions" (Surat An-Nur, (verse 24)). Also Allah (swt) says what could be translated as, "And they will say to their skin: "Why did you bear witness against us?” They will say "Allah has caused us to speak, as He cause all things to speak." (Surat Al-Fussillat, Verse 21.)
Also Allah (swt) will ask us in the Day of Judgment about all of our convenants and promises that we have made in our lives. Those promises may be made to Allah (swt) or made to people. And so Allah (swt) says in what could be translated as, “And fulfil (every) covenant. Verily! The covenant, will be questioned about.” (Surat Al-Israa, Verse 34.)
Allah (swt) will also ask us in the Day of Judgment about our hearing, our vision, and our hearts. He will ask us about how we utilized each of them. Allah (swt) says in the Noble Qur'an, in what could be translated as, “Verily! The hearing, and the sight, and the heart, of each of those, you will be questioned (by Allah). ” (Surat Al-Israa, Verse 36.)
It is out of the Mercy of Allah (swt), that he told us about these important questions ahead of time so that we can prepare ourselves. The good believer is the one who prepares himself for those difficult events by getting closer to Allah (swt), by doing good deeds, and by staying away from what Allah has forbidden, so that he will be among those who receive their book of deeds on the Day of Judgment in their right hand and Allah will enter them into paradise.