One important quality of the Quran is that it gives us only basic, but essential principles, often resorting to reiteration to emphasize them. On the contrary, non-basics, or matters relating only to form, constitute only a negligible part of the scriptures. This is in consonance with the Quranic scheme, the importance of form being entirely secondary. To the Quran, only those precepts are important which figure as fundamental guidelines. This aspect of the Quran is so clear that its reader cannot but appreciate it.
The truth is that the inner spirit is of the utmost importance in the building of the Islamic personality. Once the inner spirit is developed, correct form will naturally ensue. But form on its own can never produce the inner spirit. That is why the aim of the Quran is to initiate and bring to fruition an intellectual revolution within man. The expression used by the Quran for this intellectual revolution is ma‘rifah (realization of Truth) (5:83).
The Quran stresses the importance of man’s discovery of Truth at the level of realization. True faith in God is what one achieves at such a level. Where there is no realization, there is no faith.
Source: Quran Pocket Guide