Quran

This verse nullifies all religions other than Islam. Ibn Juzay: 1/151.
Question: How do you respond to one who claims that the followers of Judaism and Christianity are not disbelievers?

Allah makes clear that the religion that He is pleased with and accepts from His servants is Islam, and it will only be approved and accepted by Him when faith is combined with action. Ibn Taimyah: 2/96.
Question: When is religion accepted by Allah?

Hence, these people will not be granted guidance, because the one who is expected to be guided is one who did not know the truth but is keen to seek it. Such person is deserving of being shown the path of guidance and being protected from misguidance by Allah. Al-Saadi: 137.
Question: What type of disbelievers from whom guidance and faith are expected?

Meaning: The proofs and evidence were established, testifying to the truth of what the Messenger brought them. The truth was thus explained to them, but they reverted to the darkness of polytheism. Therefore, how can such people deserve guidance after they willingly leapt into utter blindness. Al-Kathir: 1/359.
Question: Why are those described in this verse unworthy of guidance?

They will not be helped to repent in any acceptable manner; rather Allah will prolong them to wander blindly in their transgression. Such people have barred themselves from taking measures of attaining their Lord's mercy, and they are the ones who blocked the way to repentance for themselves. Al-Saadi: 137.
Question: The repentance of those described in this verse is not accepted. Why?

That is because Allah has set a seal upon their hearts, hence they will not turn to Allah in sincere repentance that will endure and enable them to mend their ways. In another interpretation, there is no acceptance as they never repented because they exceeded those who are previously mentioned with their self-indulgence. Al-Biqai: 2/123.
Question: Why is the repentance of one who repeatedly disbelieves after his faith not accepted?

Abu Omran said: I heard Anas bin Malik (t) narrating that the Prophet (r) said, "Allah will say to the person with the least punishment in Hellfire on the Day of Resurrection: "If you had everything on earth, would you ransom yourself?" He will say: "Yes." Then, Allah will say, "I wanted something easier from you than this while you were in the backbone of Adam, that you not associate anything with Me, but you persisted in worshiping others besides Me." Al-Baghawi: 1/380.
Question: What will be said to the one with the least punishment in Hellfire on the Day of Resurrection?