Many different viewpoints and details have been presented regarding the explanation of religion by Westerners. In the holy Quran, the word “din” (religion) has been used for two meanings: 1- Any type of belief in an unseen power, regardless of whether such a belief is right or not: لکم دینکم ولى دین 2- Divine religions in particular: ان الدین عندالله الاسلام.
When we use the word “religion”, we are referring to the latter. Divine religions each are of different levels and categories, such as the “nafsul-amri” religion and the “mursal” religion.
Many different viewpoints have been presented by Westerners on the explanation of “religion”. John Hick has listed some definitions for the term “religion” in his book on the philosophy of religion:
1) Psychological definition: Religion is a set of feelings, experiences and actions that one has when he/she is alone with what he/she calls divine and God. (William James)
2) Sociological definition: A set of beliefs, actions, slogans and religious structures that man has built throughout history in different societies. (تالکوت پارسونز)
3) Naturalist definition: A set of negative and affirmative commands that prohibit us from freely making use of our potentials, (اس. رایناخ) or “religion and morals are the same thing, which have become of warmth and illumination through us showing feelings and emotions towards them. (Mathew Arnold)
4) Religious definitions such as: “Religion is to admit to the fact that all creatures are the manifestation of a power that is beyond our comprehension and knowledge.” (Herbert Spencer)
The variety that can be seen in these definitions has caused Western theorists and thinkers to say that the term “religion” isn’t one with a meaning accepted by all, and that there are many different concepts that go under this category, which have some things in common that Ludwig Wittgenstein names “family resemblance”.”
In the Quran, this term has been used for two meanings:
1) Any belief in an unseen power, regardless of whether such a belief is right or not: لکم دینکم ولى دین 
2) Divine religions in particular: ان الدین عندالله الاسلام 
What we mean by the term religion, is this second meaning, which refers to divine religions and has different levels and categories, such as the “nafsul-amri” and “mursal”.
For further reading:
Mahdi Hadavi Tehrani, Velayat va Diyanat, The Cultural