The Quran is the word of God, and it is a book for studying, understanding, and acting in accordance with, in order for mankind to maintain a prosperous life. However, the comprehension and meaning of all of the ayats are not the same. Some verses are easy to comprehend, while others are difficult, and others yet extremely difficult and only elite individuals like the Prophet and the Masoomeen are able to take on such a responsibility. If people who live during the time of the Masoomeen (Peace be upon them) are educated, then each one of them can refer to the verses of the Holy Quran and be able benefit from some of the concepts in it, of course to the extent of their own knowledge. However for an exact and complete grasp and understanding of all of the verses, and their interpretations and introspective meanings, we must seek help from the Prophet and the Immaculate Masoomeen (Peace be upon them).
The Holy Quran is the revealed word of the Lord, and it is a book of life with instructions in its verses on how to live properly. In actuality, when Man recites Quran, God is speaking to him and he must try to understand the word of God, just as God has invited man to think about and reflect on these verses. However we must take into consideration that the concepts in the ayats of Quran are not all one and the same, rather some ayats are comprehendible in all times and all places while others have deep meanings which are not understandable for even selected individuals. And the third type of ayats are those which have extremely profound concepts which only elite individuals can comprehend. It states In the Holy Quran: It is He who has sent down to you the Book. Parts of it are definitive verses, which are the mother of the Book while others are metaphorical. As for those in whose hearts is deviance, they pursue what is metaphorical in it, courting temptation and courting its interpretation. But no one knows its interpretation except Allah and those firmly grounded in knowledge (Rasekhoon Fil Ilm); they say, 'We believe in it; all of it is from our Lord.' And none takes admonition except those who possess intellect.
Imam Baqir (Peace be upon him) said," The Prophet Muhammad (Peace be upon him) was the most grounded in knowledge, and he recognized everything which Allah revealed to him as the interpretation and revelation of the Quran. God never revealed anything to him which he did not teach him the interpretation of, and he and all of his executors understood this.
Based on the people who lived during the time of the Masoomeen (P.B.U.T.), if they knew the language of the Quran (Arabic), and they could comprehend the meanings, then each person, in accordance with the amount of knowledge they had, could refer to the Quran and benefit form it's concepts. Nevertheless, because their understanding was not to the extent of the Noble Prophet (P.B.U.H.) and the Immaculate Imams (P.B.U.T.), then in order to comprehend the exact profound meaning in the Quran it was necessary for them to refer to the Prophet and the pure Masoomeen, and to ask them about these deeply profound meanings, their commentary and the reality and truth within the Quran.