The God made human his successor and therefore introduced means for his guidance. One of those means is the holy Quran. After the descent of the Quran, the book of guidance for all, some people accepted it and some others didn't. It should be investigated what were the roots and backgrounds which caused the oppositions and the pagans to deny Quran's verses. What was the reason? What was the content of the Quranic teachings that some people did not wanted to accept? In this paper, with an analytic and descriptive approach, using Quranic verses and library sources, we search for an answer to the above questions. Investigating and studying Quranic verses show that some roots of denying Quran are: heresy of the pagans, their obstinacy, malice, arrogance, Worldly attachments, insisting on the material beliefs, denial of resurrection, and their mistaking the values.
)