Something I see very commonly is people making generalizations about religion. These generalizations rarely, if ever, apply to religion as a whole, and frequently aren’t true for a large fraction of world religions. In part, I think this is due to misunderstanding what religion is.
Religion is not synonymous with theism, although I often see other atheists using the words interchangeably (this is even something I have done myself, although not so much recently). Theism, while a common component of religion, is not a necessary part of religion. There are many non-theistic and even some atheistic religions. In non-theistic religions, belief or non-belief in some sort of god(s) is not a central focus, or the question of whether the religion is theistic just doesn’t apply very well. Individual adherents or branches of a non-theistic religion might be atheistic, agnostic, monotheistic, polytheistic, pantheistic, alatrist, etc. Buddhism and Hinduism are examples of religions often described as non-theistic, and both have atheistic branches. Wicca has some atheistic forms as well, although most Wiccas tend to be polytheistic or pantheistic. In Satanism, the main divide is between theistic and atheistic Satanism. However, Satanism is more like a family of related religions than a single religion with diverse branches or denominations; there are some trends that are generally true of a majority or significant fraction of Satanic religions, but the only thing I know of that all Satanic religions have in common is that they use the word ‘Satanism’–but even that doesn’t work, because the Temple of Set is an exception. The Setians may not call themselves Satanists, but, fairly early on in the history of religious Satanism, they split off from the Church of Satan (commonly regarded as the first Satanic religion and, incidentally, one of the atheistic Satanisms).
Even among theistic religions, ideas of what comprises deity/divinity/god(s) vary wildly. In the Abrahamic faiths, you get an all-powerful, all-good creator god. In ancient Greek religion, you get a whole pantheon of gods, complete with infighting. In Buddhism, you (might) get some minor gods. They might or might not even be considered as superior to humans, they certainly aren’t all-powerful or all-good, and they didn’t create the universe. And then you get religions with beliefs like pantheism, where the world and deity/the divine are the same thing, and panentheism, where deity/the divine is within everything in the world (or the other way around). There are just so many wildy different ideas about what constitutes god(s)/deity/the divine, that some people even see the word ‘god’ as meaningless because it can’t be defined in a clear and consistent way.
Another thing not all religions have is a holy book. I was actually quite surprised the first time I found out about this. Growing up in the US, every single religion that I had been exposed to in more than a purely superficial way had a holy book or books. Christianity, Mormonism, Judaism, Islam, they all have holy books. In fact, they’re all Abrahamic faiths, too. And no wonder I had such inaccurate assumptions about religion as a whole, when the only religions I was familiar with all belong to the same family. I think this is the same reason that a lot of people make inaccurate generalizations about religion as a whole–they have only been exposed to a small, non-representative sample of religions. And while such a generalization might well be true about all of the religions known to them, and it might even be a common trend for religions generally, it almost certainly won’t apply to every religion.
Even among religions which do have a holy book, not all are treated the same way the Bible is for Christians. Even among Christians, there are differences in how the Bible is treated. Some hold that the Bible is literally true and infallible, while others say that the Bible is divinely inspired but was written by (fallible) men, and that certain parts are meant as allegory (especially bits which look bad, like all those genocides Yahweh called for in the Old Testament, or parts which conflict with our scientific understanding of the world, such as Noah’s ark).
And even though Christians and Jews use some of the exact same writings for their holy books, they certainly don’t read them the same way. In fact, I know less than nothing about how Jews read the Tanakh, as I have only ever read or heard about any parts of it in a strictly Christian context. And, if nothing else, it’s readily apparent that Jews (other than Messianic Jews) and Christians have come to very different conclusions about the parts of those texts which prophesy a messiah. And, given that Christians typically put more emphasis on the New Testament than the Old Testament, those texts which Christianity shares with Judaism are typically interpreted in light of a text which is not shared between the two.
Regardless, holy texts in Abrahamic religions are generally seen as divinely inspired, prophetic revelation, or the literal word of God. Other religions take quite a different approach to their holy text. Some might see a religious text as simply something written by a person, a product of its time to be used as inspiration, or even disregarded entirely, rather than interpreted as absolute truth. This is how The Satanic Bible is seen by many Satanists. Although The Satanic Bible has had a strong influence on Satanism (and there are certainly some Satanists who do take it seriously), many Satanists ignore it entirely, take it with a grain of salt, read it for entertainment or inspiration, see it as just some other religion’s (un)holy book, or find it wanting and decide to try to write a better one.
Wicca also has a very different approach to religious texts than the Abrahamic religions do. Wicca doesn’t really have a holy text per se, but Wiccas do typically have something called a Book of Shadows, which is basically a grimoire. These Books of Shadows are typically different from person to person or coven to coven. People are encouraged to modify them as they see fit, and may add new spells, take out old ones, or modify things as they please.
Man, I’m at 1000 words, and I have only even covered two things that are typically thought of as part of religions, but which not all religions have. There are many more. In fact, religion is a notoriously difficult thing to define, which scholars have been arguing about for ages. As such, it’s usually better to leave out words like ‘all,’ ‘every,’ ‘never,’ and ‘always’ when talking about religions, as there are almost always exceptions. Or you might get someone like me (a religious atheist) complaining that “hey! that’s not true of my religion!”