Memes

Because there only ever is one interpretation of any text and religious people famously all agree on it.

Because everyone who professes to a given religion has access to, reads and observes the texts and definitely doesn't just go with whatever everyone else is doing and saying and getting their religious belief through osmosis.

Because different sects and cultures don't weigh some parts heavier than others and local cultural practices and superstitions play no role in how people observe or ignore the text.

Because the text is the only thing that defines a religion and there is nothing else to it.

And of course because you definitely understand the text by just skimming it until you find whatever verse lets you feel euphoric through enlightenment by your own intelligence.