Not just interpretations of the same contradictory book. But believing your own set of myths are "real" while all other sets of myths are "false". Every theist believes that their god is the only true god and all the other gods that humanity have ever invented are false. The amount of arrogance it takes for a person to convince themselves of this fallacy is breathtaking.
Because people who do this also are dumb enough to think their religion is correct and people who do that think they know right from wrong while all they know is what the book says which has always been pretty horrible with the exception of the few common sense stuff that is added to it and disregarded or redefined by every generation. And people like that do horrible things and never know they did anything wrong. They are too lazy to think for themselves so they substitute nebulous group think for focussed independent thought and never question it. They are scared to question what their brainwashing has made them believe. They are the scum of the earth and make life miserable for so many innocent people around them judging results instead of intent or doing horribly cruel and inhumane things thinking they are doing good while they are only doing bad. Fyg
It is stupid to not realize there are other valid interpretations. Really any interpretation is just a tool, which can be used to suggest certain responses, certain courses of action. It is important to be aware of other valid interpretations so you can make your arguments more effectively and also so you can be open to reexamining the evidence and drawing new conclusions if warranted.
For those saying "but you have to believe in what you believe is correct" by definition this is true however you can recognize that a number of different opinions could actually be right while knowingly gambling on the one you prefer based on educated guessing and a weighing of known potential risks and benefits.
It is common for people to view the same thing and have some different descriptions of what they saw. To compound matters, if a story is retold, it tends to be changed slightly each time it is passed on word of mouth. Even without various religions that take passages to mean different things, these inconsistencies exist. For instance, when some of the people wrote of the life of Jesus, their stories were not consistent from one telling to another. To make matters worse, the scriptures needed to be translated. Because some words have multiple meanings on both side of the translation, it would be easy to see how what was originally meant was altered over the years and translations.
Though it could be that the use of words with multiple meanings was unintended, I think it may have been intentionally vague. Look at it this way, if things are too specific, it may alienate people some people may not easily identify with the meaning. If it is vague, more people feel included. Here is an example: If I throw a party and say everyone who is popular can come. Any who feel they may be popular would show up. If I say that I am inviting the most popular. The less popular would not feel invited. By keeping meanings vague, you invite more people. The more that come, the larger the group. This tactic may have been intended to grow the religion faster. The problem arises when the group gets too large. In the party example: The popular kids would split off into what they consider is popular. Jocks gather with jocks, hipsters with hipsters, and so on. Next thing you know, each group is claiming their group is the popular group. A similar thing has happened with various religious groups. Though they may have started as a small group of people, once the group gets too large people take sides as far as what was actually meant.
Everyone believes that they are correct in their beliefs. If they did not believe they were correct, then those wouldn't be their beliefs.
This doesn't just apply to religious beliefs, but absolutely all of them of any kind; political, moral, social, economical, or ethical. Many beliefs require faith, for when it comes to things no man can possibly know for sure, we all have faith in something.
We will all believe what we do despite others having contradicting beliefs, and it's not "stupid" until it's your own beliefs that contradict each other.
If you have sufficient reasoning to believe that your interpretation is superior when compared to others, then why not? We have a saying in Chinese, 'if you have reasoning, your ideas can walk to every place under the heavens; if you do not have reasoning, your ideas cannot even proceed a single step.' If you have perfectly good reasons to believe that your interpretation is better, such as through philological studies of the semantic content of the words used, then I don't see why not.