One must believe, beyond any doubt, that only Allah Almighty is worthy of worship and The Creator of the universe and the Handler of all things in Heavens or on Earth. He has the best names and the highest characteristics. He Almighty is The Creator and The Sustainer, He is the Benefactor , The Giver and the Taker, The Most Able. This belief is given the term ‘the unification of divinity' (tawheed ar-rooboobiyyah).
The unification of divinity alone would not admit one into the fold of Islam. Together with that, faith must be shown that Allah Almighty alone is deserving of worship and no one else, and that is the meaning of "Laa ilaaha illa Allah." This is the unification of worship (tawheed al-'ibaadah) with the faith in the unification of the names and the characteristics (tawheed al-asmaa was-sifaat). One must have faith that Allah Almighty is The Most Perfect in Himself, in His Names, in His Characteristics and in His Deeds. He has the Absolute perfection who has no partner and none similar and there is none like unto Him.
What we must believe
The two worlds, that of men and that of jinns must believe in the names and the characteristics of Almighty Allah mentioned in the Holy Qur'an such as the Almighty, The Wise, Who hears all things, the Creator, The Sustainer, The Benevolent and The Most Gracious and all the other names and characteristics. Faith must also be in what is affirmed in the Sunnah about the names of Almighty Allah as they were revealed with no increase or decrease.
One must also believe that Allah Almighty is not like any of His creatures, and there is no similarity in shape or in entity. All the prophets unanimously had faith in all that and all the messages were descended with those teachings, the most complete of them all is the Holy Qur'an. One must also believe in Prophet Muhammad, sallallaahu ‘alaihi wa sallam, and in all the other prophets too and in all that they had narrated about the angels, the books, the question of Heaven and Hell, the Day of Resurrection, the judgment and reward, the torment or bliss in the grave, and the belief in fate.
What we must follow and prepare for
The Muslim must follow the straight path of the religion of Allah Almighty, by saying and by doing and as a creed. He must observe all the ordinances prescribed on him, and avoid all the prohibitions he is forbidden from. He must also believe all that is told by Prophet Muhammad, sallallaahu ‘alaihi wa sallam, about the states of the dead in their graves, and that the grave is either a heavenly garden or a devilish hell. Once the dead is placed inside his grave. two angels would ask him who his God is, what his religion is and who his Prophet is.
For the believers, Allah Almighty would send down tranquility into their hearts and add faith to their faith. When asked in his grave, the believer would answer my God is Almighty Allah, Islam is my religion, and Muhammad, sallallaahu ‘alaihi wa sallam, is my prophet. As the Muslim was holding fast to his faith and to his religion during his lifetime, for this reason Allah would grant him peace of mind and tranquility in his grave. But the disbeliever or the hypocrite, when asked in the grave they would find no answer to give and would say instead "I only followed what the astray people were saying."
On giving that answer, the disbeliever would be hit by a sledgehammer, and a scream would come from him to be heard by all creatures except man, who would have been frightened if could hear that. As such people would be resurrected and judged on the Day of Resurrection. When the trumpet sounds for the Last Day, all people die and are resurrected and judged in accordance with their deeds.
All this must be believed in and one must prepare for that Last Day, by the unification of Allah and following His ordinances and avoiding His disobedience. The happy ones are those who are judged and given their records in their right hands, and the unhappy are those people who are judged and given their records in their left hands.
Muslims must be prepared for that day. They must advise one another in righteousness and stay firm with truth. They must enjoin the right and forbid the wrong, as Allah Almighty said in His Holy Book:
The believers, men and women are protectors one of another, they enjoin what is just, and forbid what is evil, they observe regular prayers, practice regular charity, and obey God and His Apostle. On them will God pour His mercy, for God is Exalted in power, Wise. [Surah Al-Ma'aarij: 5]
The greatest of rewards
The believers would be enabled to actually see their Lord Almighty. He, Almighty would speak to them and would let them see His divine Face. The disbelievers would be veiled as Allah Almighty said,
Verily, from (the Light) of their Lord, that Day will they be veiled. [Surah Al-Mutaffifeen: 15]
The followers of the Sunnah and Al-Jamaa'ah have all confirmed and believed in this. In the Heavens, the believers would be able to see all that in reality, in their highest of bliss. Allah Almighty said,
To those who do right is a goodly (reward) Yea, more (than in measure). [Yunus: 26]
The goodly reward is the Garden (Al-Jannah), and what is more than in measure is the opportunity to look at the Face of Allah Almighty, and enjoying that bliss and the ever lasting good which is beyond imagination. The followers of the Sunnah consider anyone to disbelieve that as an apostate. Allah Almighty will not let Himself to be seen in this word as this world is not a world of bliss but rather a world of trial and tribulation. So Allah Almighty saved the revelation of His Face for the Hereafter.
Verily, Al-Abraar (the pious who fear Allah and avoid evil) will be in delight. On thrones looking. You will recognize in their faces the brightness of light. [Al-Mutaffifeen Aayah 22 - 24]
Some faces that Day shall be Naadirah (shining and radiant) looking at their Lord. [Al-Qiyaamah 22 - 23]
The believers will indeed see Allah on Yaum Al-Qiyaamah and in Al-Jannah it will be a great sight. This seeing of Allah is not all encompassing however because Allah is too Majestic and Great to be encompassed by any vision of His creation as Allah has stated:
No vision can grasp (yudrikhu) Him, but His Grasp is over all vision. He is the Most Subtle and Courteous, Well-Acquainted with all things. [Al-An'aam 103]
The meaning of this is that their vision will not encompass Him because al-idraak (as mentioned in the previous aayah) is particular while ar-ru'yah is general. As Allah stated in the aayah:
And when the two hosts saw (taraa'aa) each other, the companions of Musa said: "We are sure to be overtaken." [Ash-Shu'araa 61]
Allah makes clear that seeing (At-Taraa'ee) is not grasping (Al-Idraak). A group of the salaf (pious generations) explaining the previous aayaat, among them ‘Aaisha (radiallahu ‘anhaa), said that what is intended is that they (the believers) would not see Him in this world (as-dunyaa). There is no argument for those among the innovators (ahlul-bid'ah) because of other Qur'anic ayaat which have been explained previously along with authentic ahadith that are mutawaatir (so widely reported that there is no chance of error) absolutely confirm that the believers will see their Lord on the Day of Resurrection and in Al-Jannah. The companions were in consensus about that as were their followers among Ahlus Sunnah and that which was held by the Jahmiyyah and the Mu'tazilah (later deviant sects) is wrong and unaccepted. What they stated was the worst of wrongs and most astray. We ask Allah safety and security from their trial and we ask Allah for us and those who uphold tawheed (al-muwahhideen) understanding and guidance and always returning to the truth.
Prophet Muhammad, sallallaahu ‘alaihi wa sallam, said, "Know that, no one of you would see His Lord until he is dead." The Muslim has to believe all that and all that was narrated by Prophet Muhammad, sallallaahu ‘alaihi wa sallam. As for the disobedient Muslim, is in danger of torture, but he would eventually be admitted in, even though he would)d be entered in Hell because of his disobedience. He would not stay in it for ever; but he would be pardoned and entered in Heavens, as indicated in the Hadith about Prophet Muhammad, sallallaahu ‘alaihi wa sallam, the Muslim is subject to the redemption of Allah Who said:
Allah forgives not that partners should be set up with Him, but He forgives anything else, to whom He pleases. [Surah An-Nisaa: 48]
If Allah pleases, He would forgive him and admit him in Heavens with his brothers from the beginning, if not forgiven he would be tortured in Hell according to the sins he had committed and after sanctification he would be admitted in Al-Jannah. He might be tortured in his grave or might be saved until doomsday, for committing the cardinal sins such as drinking wine, committing adultery, being disobedient to one's parents and the like. The one who declares penitence before his death, he would be placed by Almighty Allah with his brothers from the first instance, as a reward to him.
By Shaykh Abdul-Aziz Abdullah Ibn Baz (rahimahullah)