The King of the Day of Judgment… (Surat al-Fatiha, 1:3)
On the Day of Judgment, people will be resurrected and gathered together to account for their deeds. On that Day, they will have neither the will nor the opportunity to pay attention to the people around them, whether they are their parents, spouses, or children. Due to this Day's fearsome nature, everyone will pay attention only to themselves, for:
What will convey to you what the Day of Judgment is? Again! What will convey to you what the Day of Judgment is? It is the Day when a self will have no power to help any other self in any way. The command that Day will be Allah's alone. (Surat al-Infitar, 82:17-19)
On that Day, anything to which a person attaches too much attention will be reduced to insignificance. From then on, any mundane relation or kinship will lose all importance, for the only value that will remain is one's faith in Allah. No one will be able to help another person, for only Allah, if He wills, can save a person from this detrimental situation.
Each of us will be alone before Allah's presence, the Owner of the Day of Judgment, just as we were alone when we were first created. Each of our deeds and thoughts will be displayed on the Day of Judgment, for He never forgets any detail, no matter how small. Allah creates a setting that befits His Honor and calls His servants to account. However, He saves anyone He wills through His mercy.
On this Day, when unbelievers will be overwhelmed by a grievous regret, believers will be joyful and exuberant:
... On the Day when Allah will not disgrace the Prophet and those who had faith along with him... (Surat at-Tahrim, 66:8)
That is because “Allah will certainly help Messengers and those who believe both in the life of the world and on the Day the witnesses appear.” (Surah Ghafir, 40:51)
The sole king of that Day is Allah, for He is the only One Who can command. The related verses read:
There will be but one Great Blast, and then their eyes will open. They will say: “Alas for us! This is the Day of Reckoning!” This is the Day of Decision you used to deny. (Surat as-Saffat, 37:19-21)
Woe that Day to the deniers, those who deny the Day of Reckoning. No one denies it except for every evil aggressor. (Surat al-Mutaffifin, 83:10-12)