All perfect praise be to Allaah, The Lord of the worlds. I testify that there is none worthy of worship except Allaah and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.
It is better for you to strive in calling these people to Islam by acquiring profound religious knowledge and making a Da‘wah (proselytization) program wherein you hold discussions with non-Muslims to teach them about Islam and introduce them to the Truth. The Prophet, sallallaahu ‘alayhi wa sallam, said, "If a single person is guided by Allaah through you, it will be better for you than the red camels (the most valuable camels)." [Al-Bukhari]
As for declaring non-Muslims as Kaafirs (disbelievers) and judging their fate in the Hereafter with certainty, you should know that if the message of Islam has reached a person but he chooses to disbelieve in it, then there is no doubt that he is Kaafir and shall abide in Hell eternally. This applies whether he recognizes the truth but chooses to deny it or he turns away from it without trying to know it, and whether he was edified on the details of the teachings of Islam and recognized its beauty or was merely informed of the divine message of Islam revealed to the Prophet Muhammad, sallallaahu ‘alayhi wa sallam, without being informed of the details of the teachings of Islam and its beauty. There are two statements to be made regarding such a person; the first is the ruling on him in this World, and the second is the ruling on him in the Hereafter. In this world, he is ruled as a Kaafir because he has not accepted Islam to begin with. In the Hereafter, the preponderant view is that he shall be tested on the Day of Judgment. Imaam Ahmad narrated in his Musnad that the Prophet, sallallaahu ‘alayhi wa sallam, said:
"Four types of people will be tested on the Day of Judgment: a deaf man who cannot hear anything, a mad man, an old-aged man, and a man who died during Fatrah (a period of time when no messenger was sent to people). The deaf man will say, 'My Lord, Islam came while I cannot hear anything!' The mad man will say, 'My Lord, Islam came while the boys were throwing dung at me!' The old-aged man will say, 'My Lord, Islam came while I could not understand anything!' And the man who died during Fatrah will say, 'My Lord, no messenger came to me.' Allaah will take a promise from them to obey Him, then He will command them to enter Hellfire. By Him in Whose Hand my life is, the one who enters it will find it cool and safe..." [Ahmad - Al-Albaani graded it saheeh (sound)]
The fact that the Kaafirs shall abide in Hellfire eternally is stated in many verses in the Quran, including the following:
Allaah, The Exalted, says (what means):
- {Indeed, those who disbelieve and commit wrong (or injustice) - never will Allaah forgive them, nor will He guide them to a path. Except the path of Hell; they will abide therein forever. And that, for Allaah, is (always) easy.} [Quran 4:168-169]
- {Indeed, Allaah has cursed the disbelievers and prepared for them a Blaze. Abiding therein forever, they will not find a protector or a helper.} [Quran 33: 64-65]
- {Indeed, they who disbelieved among the People of the Scripture and the polytheists will be in the fire of Hell, abiding eternally therein. Those are the worst of creatures.} [Quran 98:6]
Believing in the truthfulness of what is stated in these texts is a prerequisite of Eemaan (faith). Whoever believes in Allaah as his Lord and in Muhammad, sallallaahu ‘alayhi wa sallam, as the Messenger of Allaah must essentially believe in the truthfulness of whatever Allaah and His Messenger say, including the fact that the disbelievers shall abide in Hellfire eternally. This ruling applies to the disbelievers collectively in general terms.
It has been authentically reported that the Prophet, sallallaahu ‘alayhi wa sallam, said, "By Him in Whose hand the life of Muhammad is, the one amongst the community of Jews or Christians who hears about me but does not affirm his belief in that with which I have been sent and dies in this state (of disbelief) shall be but one of the denizens of Hellfire." [Muslim] He also said, "None shall enter Paradise except a Muslim soul." [Al-Bukhari and Muslim]
An-Nawawi commented on the hadeeth, saying, "This hadeeth is an explicit text indicating that whoever dies while harboring disbelief shall never be admitted to Paradise to begin with. This text applies to the disbelievers collectively in general terms according to the consensus of Muslims..." [Sharh Muslim]
As for judging with certainty that a specific individual shall be among the dwellers of Hellfire, it is impermissible except if it was established via divine revelation clearly stating that he shall be among the people of Hellfire. Shaykhul-Islam Ibn Taymiyyah wrote:
"The reported view of Imaam Ahmad cited by Al-Khallaal is that it is allowable to invoke the curse of Allaah on the disbelievers in general and not on a particular individual or individuals, as underlined in the texts on the warnings in this regard. The same applies to judging that a particular individual shall be among the dwellers of Paradise or Hellfire. We believe that the believers, in general, shall be admitted to Paradise and that the disbelievers, in general, shall be in Hellfire. We also believe that those whose fate in the Hereafter is clearly stated in the Quran or Sunnah, whether it be in Paradise or Hellfire, will face such a fate as has been established through divine revelation. However, we do not believe that we can judge with certainty that a particular individual shall be among the people of Paradise or Hellfire unless there is a religious text to this effect or it is proven through many statements of a large group of reliable scholars to this effect..."
Shaykh Ibn Jibreen said:
"As for judging with certainty that a specific individual is declared among the dwellers of Hellfire, it is impermissible to judge as such unless there is a religious text to this effect. For instance, a verse has been revealed stating that Abu Lahab shall abide in Hellfire. Allaah, The Exalted, says (what means): {He will (enter to) burn in a Fire of (blazing) flame.} [Quran 111:3] Moreover, when Abu Jahl was killed in battle, the Prophet, sallallaahu ‘alayhi wa sallam, looked at the people of the well, in which the bodies of the disbelievers killed in the Battle of Badr were buried, and said, 'Have you found true what your Lord promised you? I have, surely, found what my Lord promised me true!' The Prophet, sallallaahu ‘alayhi wa sallam, also said about Abu Taalib, 'He is in a shallow place of Hellfire...' [Al-Bukhari] In brief, when there is a reported religious text stating that a particular individual is among the dwellers of Hellfire, then the Muslims can judge with certainty that he will be among dwellers of the Hellfire."
Shaykh Ibn ‘Uthaymeen wrote:
"Judging that someone will enter Hellfire is of two kinds: general and specific. We can judge with certainty that the disbelievers, in general, will be dwellers of Hellfire, as evidenced by the verse that reads (what means): {Indeed, those who disbelieve in Our verses - We will drive them into a Fire...} [Quran 4:56] As for the specific individual, we cannot judge with certainty that a particular disbeliever will be among the dwellers of Hellfire. There must be a religious text to this effect, such as the texts stating that Abu Lahab, his wife, Abu Taalib, and ‘Amr ibn Luhayy Al-Khuzaa‘i shall be among the people of Hellfire..."
He also said:
"If a man passed away as a Christian according to our knowledge of his apparent state, is it allowable then to judge with certainty that he will be among the dwellers of Hellfire? No, we cannot judge with certainty that this person in particular will be among the dwellers of Hellfire. If he is among the dwellers of Hellfire, then he will be thrown into it even if we did not judge him to be as such. And if he is not among the people of Hellfire, then we would be judging without knowledge. It is pointless to discuss such issues."
The Fatwa of the Permanent Committee for Islamic Research and Fataawa reads:
"Ahlus-Sunnah Wal-Jamaa‘ah held that a specific individual cannot be declared among the people of Hellfire or Paradise unless the Prophet, sallallaahu ‘alayhi wa sallam, clearly stated that he is among the people of Hellfire or Paradise. We only hope for a good fate for the pious and fear a bad fate for the sinners. Indeed, only Allaah knows people's final stages of life and their fate in the Hereafter. It should be stressed that the Jews and Christians are Kaafirs, and whoever dies as a Kaafir, in general, shall abide in Hellfire, and whoever dies while believing in Allaah and His Messenger Muhammad, sallallaahu ‘alayhi wa sallam, in general, shall be admitted to Paradise. Allaah, The Exalted, says (what means): {Allaah has promised the believing men and believing women gardens beneath which rivers flow, wherein they abide eternally...} [Quran 9:72] Allaah, The Exalted, also says about the disbelievers (what means): {They will wish to get out of the Hellfire, but never are they to emerge therefrom, and for them is an enduring punishment.} [Quran 5:37]"
Allaah knows best.