All perceived realities are relative to the extent that they are created from an inadequate frame of reference caused by the limitations of the five senses. We do not see all sights, hear all sounds nor smell all smells. In spite of this, we go through life thinking we know what is real and what is not and that our conceptual understanding of sense based reality is valid.
A small amount of observation is enough to see that all humans are subjective and that any given experience can be perceived differently by different observers. Accepting this idea raises an important question: Is there a higher, all encompassing reality that includes our subjective realities? I would suggest the answer is yes, as an acceptance of the fact that our senses can not experience everything implies that there is literally "more than meets the eye". The structure of what we can not see must encompass and include what we can.
Once we accept the idea of a higher frame of reference encompassing an individual's lower one we can draw the following conclusion: If we understand anything at a higher frame of reference, it's usefulness to us will be enhanced in direct proportion to the amount of higher knowledge we obtain.
This idea is at the heart of mainstream religions. The assumption is that the particular religion champions a particular frame of reference that it feels is a valid part of an even greater one. It further assures that if the individual believer creates a subjective reality using this frame of reference, they can use it to live a more spiritually satisfying life.
A problem arises when a particular individual does not or can not accept the canned reality that the various mainstream religions offer. In spite of the great variety of ideas, dogmas and belief systems that exist, any particular individual may decide that none of them is right.
The ideal solution for this individual would be to be able to comprehend in a personal way the larger frame of reference that their lower subjective reality functions within. In this way, their reality would be both valid and personally satisfying. It is generally believed that understanding the greater reality of that which we are a part of is impossible without some sort of personified conceptual construct that must be accepted completely as a prerequisite to greater understanding.
In fact, the understanding required can be derived individually by using some basic concepts as tools to learn and understand what the higher frame of reference is and how to relate to it in a personal way.