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 is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.
Allaah Says (what means): {We will show them Our signs in the horizons and within themselves until it becomes clear to them that it (the Quran) is the truth. But is it not sufficient concerning your Lord that He is, over all things, a Witness?}[Quran 41:53]. Imaam Ash-Shawkaani interpreted the verse to mean: 'i.e. We will show them the evidence that the Quran is the truth and show them the signs that it came down from Allaah.' This does not contradict the fact that some people died before the call to Islam reached them, as the verse is about those whom the Quran reached but they denied it and disbelieved in it. This understanding is clear by referring to the verse which came straight before the above one. Allaah Says (what means): {Say, “Have you considered: if it [i.e. the Quran] is from Allaah and you disbelieved in it, who would be more astray than one who is in extreme dissension?”}[Quran 41:52], and then Allaah Says (what means): {We will show them…}, meaning to those who disbelieved in the Quran. That’s why Ibn Jareer said in relation to the interpretation of the above verse: 'We will show these people who deny…' However, we do not know any evidence from the Book of Allaah or the Sunnah of the Prophet that every single person will know the truth before his death. On the contrary, there is evidence that there are people who will die before discovering the truth. Indeed the Prophet said: “There are four kinds of people who would protest on the Day of Judgement: A deaf person who cannot hear anything, a foolish person, a very old person, and a man who died in the period during which there was no revelation and no message. The deaf would say: “Islam came but I could not hear anything.” The foolish person would say: “Islam came but I could not understand anything.” The very old person would say: “Islam came while I could not realize anything”. As regards the person who died during the period in which there was neither messengers nor revelation, he would say: “My Lord, no Prophet came from You. So, Allaah would take an oath from them in His Name that they would obey Him, then Allaah would order them to enter Hellfire. Whoever enters it, it would be for him peace and cold, and whoever refuses to enter it, will be dragged to it.”
For more benefit, please refer to Fataawa 85624 and 86712; Shaykh Dr. Billaal Phillips explains to whom the verse refers.
Allaah Knows best.