Introduction: On the Quran’s Comprehensive, All-Encompassing Qualities
Allah has endowed His Book with exalted and magnificent attributes that apply to it in its entirety, demonstrating beyond doubt that it is the root and foundation of every beneficial science and every discipline that steers humanity toward the welfare of this world and the next:
• He has named it guidance, rectitude, the criterion, and declared it clear in itself and a clarification of all things.
• In and of itself it is guidance, directing all created beings to everything they need for their religious and worldly affairs.
• It leads them to every beneficial path.
• It distinguishes for them between truth and falsehood, guidance and misguidance, and between the people of felicity and the people of misery by describing the hallmarks of each group.
• It lays out both fundamentals and ancillary matters, furnishing their textual and rational proofs.

Thus, in many verses He invests it with these absolute, universal qualities from which nothing at all is excluded.

Yet in other passages He restricts its guidance with several conditions: it is guidance for the believers, the people of piety, for those who reason and reflect, and for whoever truly seeks the truth. With this the Exalted One elucidates the prerequisite for benefiting from its guidance—namely, that the recipient must be receptive and responsive. Guidance requires intellect, contemplation, and thoughtful reflection upon its verses. Whoever turns away, refusing to think and reflect on its signs, will not benefit from it; and whoever does not seek the truth, has no real desire for rectitude, but rather harbors a corrupt intention and has steeled himself to resist and oppose it, will receive no share of its guidance. The first is denied guidance because the condition is absent, the second because a barrier is present.