The Quran presents itself as a divine revelation in which there is no doubt, serving as guidance for the God-fearing (Muttaqin). As Ibn Kathir explains, "The Book, is the Qur'an, and Rayb means doubt... The meaning of this is that the Book, the Qur'an, is without a doubt revealed from Allah." This guidance, however, is primarily for those who possess Taqwa, a fear of Allah and refraining from transgressing His commands, encompassing belief in the unseen and certainty in the Hereafter, as detailed in 2:4.

Despite the clarity of divine truth, the Quran describes various forms of its rejection. For those who disbelieve, it is the same to them whether you warn them or do not warn them — they will not believe. Ibn Kathir clarifies that this refers to those whom Allah has decreed to be miserable due to their stubbornness and denial, not a general inability to believe. The hearts of such individuals are described as sealed, their hearing stopped, and their eyes covered, preventing them from perceiving the truth “as if they had not heard them”. Ma'arif-ul-Quran explains this sealing as a form of divine punishment for willful disobedience, where their own arrogance and evil deeds gradually destroy their capacity to accept truth, akin to rust covering a heart as mentioned in the verse.

The Quran identifies several root causes for the rejection of truth. One significant factor is arrogance, often manifesting as a refusal to acknowledge the prophethood of Muhammad ﷺ, despite clear signs. For instance, the Jews, though they recognized the truth of the Quran as confirming their own scriptures, disbelieved in it out of envy and fear of losing leadership, as highlighted by Ibn Kathir. This denial, even with knowledge, renders them "infidels" (Kafirin), because true faith (Iman) requires not just knowing the truth but actively accepting and affirming it in deeds. Satan, too, knows the truth but rejects it out of arrogance.

Another major impediment is blind adherence to ancestral traditions. When urged to Follow what Allah has revealed, many would retort, Rather, we will follow that which we found our fathers doing. This uncritical following is condemned, especially when "their fathers understood nothing, nor were they guided." Ibn Kathir illustrates this by relating how some Jews, when invited to Islam, refused, stating they would adhere to their forefathers' practices, despite those practices being based on no sound understanding or guidance. This theme is reiterated in various surahs, such as when it is said, Sufficient for us is that upon which we found our fathers, even if their ancestors "knew nothing, nor were they guided."

Envy also plays a destructive role. The People of the Scripture, particularly the Jews, are depicted as being envious of the Prophet Muhammad ﷺ for the prophethood and bounties Allah bestowed upon him. They would even prefer disbelievers over Muslims, saying, These people are better guided on the way than the believers, as narrated in Tafsir Ibn Kathir regarding Ka'b bin Al-Ashraf and Huyay bin Akhtab. This envy drove them to reject him because he was an Arab, not from the Children of Israel, even though they knew his description from their own scriptures.

The Quran details severe consequences for those who reject the truth. For the disbelievers, a severe torment awaits them on the Day of Resurrection. This torment is not merely physical but also a profound spiritual loss, as their deeds in this world are rendered worthless, lost in this world and in the Hereafter. As Ibn Kathir explains, "Allah will punish him for his rejection, reckon him for his denial, and torment him for defying His Book."

For hypocrites who outwardly claim faith but inwardly harbor disbelief, their deceit is a form of mischief, confusing believers and supporting disbelievers (2:11, Tafsir Ibn Kathir). Allah mocks at them and leaves them increasing in their deviation to wander blindly. This divine "mockery" is a just punishment, a retribution for their cunning. Their fate is described through parables of those who lit a fire for light, but then Allah removed their light, leaving them in darkness, deaf, dumb, and blind, unable to return to guidance (2:17-18, Tafsir Ibn Kathir).

The rejection of truth can also lead to a hardened heart, becoming like stones or even worse in hardness. Such hearts, unlike certain stones from which rivers gush forth or water issues, are unmoved by signs or admonishment. Ibn Kathir clarifies that inanimate objects can possess a degree of awareness, citing verses like Had We sent down this Qur'an on a mountain, you would have seen it humble itself and split apart from fear of Allah. Thus, the hardening of hearts in humans is a severe spiritual ailment, making them incapable of receiving guidance.

The Quran frequently uses the narrative of the Children of Israel to illustrate various forms of truth rejection. Despite receiving numerous blessings and clear signs from Allah, they often exhibited stubbornness and disobedience. They were delivered from Pharaoh's people who afflicted them with horrible torment, and Allah even separated the sea for them to save them. Yet, shortly thereafter, they worshipped a calf in Musa's absence (2:54, Tafsir Ibn Kathir). Their repentance for this act was so severe that they were commanded to kill each other as a form of atonement.

Their defiance continued with their reluctance to follow divine commands, such as when they were ordered to sacrifice a specific cow. Instead of prompt obedience, they disputed the command and asked numerous unnecessary questions, making the task difficult for themselves (2:68-71, Tafsir Ibn Kathir). This stubbornness is contrasted with the simplicity of belief.

Another example of their rejection was their attitude towards the Sabbath. They breached the sanctity of the Sabbath through deceitful means to catch fish, leading to their transformation into "monkeys, despised and rejected." This physical metamorphosis, as explained by Tafsir Ma'arif-ul-Quran, was a literal punishment, not merely a psychological one, serving as a warning to others.

The People of the Book also exhibited a selective belief, saying We believe [only in what was revealed to us] while disbelieving in later revelations like the Quran. This selective acceptance is further condemned by reminding them of their forefathers who “killed the prophets of Allah before” despite claiming belief in earlier scriptures. This highlights their inconsistency and deliberate rejection of truth.

Despite the dire warnings, the Quran always keeps the door of repentance open. Allah is Oft-Forgiving, Most Merciful. Repentance is accepted as long as the soul has not reached the throat (4:17, Tafsir Ibn Kathir). This mercy is a testament to Allah's kindness, encouraging individuals to turn back to Him, even after prolonged disobedience.

The path to accepting truth is clear: unwavering belief in Allah, His Messengers, and His Books. It requires embracing Islam, which means total submission and obedience to Allah alone (3:19, Tafsir Ibn Kathir). The Quran emphasizes sincere devotion, not merely oral affirmation, and warns against allowing worldly desires or ancestral traditions to overshadow divine guidance.

Ultimately, adherence to the truth brings immense rewards, including forgiveness and eternal Paradise, while persistent rejection leads to severe consequences in both this world and the Hereafter.

The concept of Rejection of Truth (رفض الحق) in Islam is a multifaceted theme deeply explored in the Quran and elaborated upon by various tafsir commentaries. It highlights the profound human responsibility in responding to divine guidance and the spiritual perils of choosing disbelief, arrogance, or blind adherence over sincere acceptance. From the explicit warnings against those who disbelieve despite clear signs to the historical accounts of the Children of Israel's stubbornness, the sources consistently emphasize that true faith requires an open heart and a willingness to submit to Allah's undeniable truth, thereby securing ultimate success and escaping severe retribution.