Religions have changed so much over time. Take any religion and see how it was practiced a thousand years back and how it is practiced today. You will find many differences.
One might argue that time changes everything. So, why should religions be different. You have to adapt to the changing circumstances. Agreed.
I strongly believe, however that the changes in a religion should not alter the fundamental principles of the religion. And this happens ever too often.
Why do such changes happen?
I believe that a section of the clergy of most religions have vested interests in promoting their own 'interpretation' of the religious texts and they promote and expound these interpretations as if they were the 'absolute truth'.
Further, they also add the rider that their interpretations are 'God's word' and going against them is equivalent to blasphemy. The laity have no option but to acquiesce.
Many of our religious texts are written in languages that are not widely spoken today. This makes it all the more difficult for common people to read the texts and get a first-hand account of what they say.
The clergy have usually studied these languages and are therefore able to read these texts and understand them. Many of these texts are also written in a form of poetry. Liberal use of analogies and maxims offer themselves for varied interpretations. Theoretically, we cannot find fault with an interpretation. But it is possible that the interpretation is at variance with what was originally intended by the author.
Another tactic used by the clergy is to tell the laity that they are not 'intelligent' enough to question the knowledge of the monks that existed hundreds of years back. So, if a group of monks laid down a law two hundred years back, they knew what they were doing. Never mind if it goes against an individual's common sense. Again, blasphemy if you question.
It is only a part of the clergy that has these traits. Definitely not all. There are many who genuinely strive for the common good without any selfish motives.
Religion is an intensely personal thing. It should not be followed due to scare of something bad happening. It should be followed voluntarily, if at all. It is there to give us peace. It is there to fulfill the need for filling up a spiritual vacuum.