In the Name of Allah, The Most Gracious, Most Merciful
The mind alone is not considered as a sufficient reference for religious matters.
As the eye is unable to see objects without light, because light enables it to see them, the mind also needs the Divine Revelation in order to be guided to the absolute truth.
The mind has limited abilities. Thus, being unable to comprehend inclusively all matters from all their sides in all times and places, makes the mind unqualified to be the only frame of reference for man.
﴾Verily, he thought and plotted; So let him be cursed! How he plotted! And once more let him be cursed, how he plotted! Then he thought; Then he frowned and he looked in a bad tempered way; Then he turned back and was proud; Then he said: "This is nothing but magic from that of old; "This is nothing but the word of a human being!"﴿
Allah indicates that the mind has limitations to its functions when He says:
﴾And of knowledge, you (mankind) have been given only a little.﴿Allah also says:
﴾They know only the outside appearance of the life of the world (i.e. the matters of their livelihood, like irrigating or sowing or reaping, etc.), and they are heedless of the Hereafter.﴿
If we showed a person who lived one hundred years ago a CD on which there are 1100 books and we tell him that this CD is capable of scanning all the letters of these books in 7 seconds, would he comprehend what we are saying to him?
No he wouldn't, because 100 years ago they didn’t have this technology, but now we have it.
This means that the comprehension of the mind is related to the environment (reality), thus not everything rejected by your mind is falsehood.
These are Allah’s Orders and Prohibitions, and if you get acquainted with the Law-Giver (i.e. Allah) you will obey Him devotedly, as Allah’s Words sublime over the words of His creations like the way Allah sublimes over His creations.
The mind sometimes submits to the pressures of the personal interests of man, and this is the nature of the justifying mind. When man fulfills his lusts, he starts using his mind in the favor of his desires, and that is why you see the people who follow their unlawful lusts trying to cover their errors with a philosophy in a way or another (in order to justify them).
﴾Have you seen him who takes his own lust (vain desires) as his ilah (god), and Allah knowing (him as such), left him astray﴿
One more thing: The senses are the only sources of the mind, Thus, the mind can’t believe intangible matters, while the Divine Revelation tells us about all the matters beyond our senses.
Therefore, the mind responds to the perceptible reality and comprehend what can be sensed only, and it can change all that into an abstract, but as for the intangible matters like the ancient world, the far future, the life after death and the other creations Allah told us about, these matters can’t be reached by the mind alone and we need the Divine Revelation to know about them.
Finally, the mind can’t oblige man to follow the right path. There are a lot of educated people who smoke. This proves that information is not enough and man is in dire need for a strong will to wisely make use of any piece of information.