You will not die; the ultimate lie of religion. Out of all the other bull****, this lie remains the single greatest force for keeping the sheep in the faith. "Human-kind has always feared what it doesn't understand". The ultimate unknowable for humans is death, so for many it stands as their greatest fear. Perhaps not an immediate fear, or even one that exists in the forefront of their minds, but when thought about for long periods of time, it can be the most terrifying thing to attempt to imagine, and that is what makes it so terrifying: you can't imagine it. This might be one of the reasons why seemingly intelligent people cling to religion, whether they realize it or not.
So as humans tend to do, when we cannot think up a logical, reasonable, scientific explanation for something, we often create ANYTHING to fill the gaps, just to have those gaps filled. Since we cannot imagine non-existence, we create a belief that endlessly perpetuates what we do understand, that of simple existence. And because humans are so incredibly stubborn in giving up traditions, even the smaller ones, it only makes sense that we would keep the traditions around that were created thousands of years ago specifically for these unanswerable questions. And since humans thousands of years ago possessed very poor moral ideals, compared with our ("our" meaning most of the developed world) modern conception of morality, these traditions upon which they so stubbornly cling to are filled with the horrid morals of humans thousands of years ago. So really, religion as it exists today is an inevitability.
So as humans tend to do, when we cannot think up a logical, reasonable, scientific explanation for something, we often create ANYTHING to fill the gaps, just to have those gaps filled. Since we cannot imagine non-existence, we create a belief that endlessly perpetuates what we do understand, that of simple existence. And because humans are so incredibly stubborn in giving up traditions, even the smaller ones, it only makes sense that we would keep the traditions around that were created thousands of years ago specifically for these unanswerable questions. And since humans thousands of years ago possessed very poor moral ideals, compared with our ("our" meaning most of the developed world) modern conception of morality, these traditions upon which they so stubbornly cling to are filled with the horrid morals of humans thousands of years ago. So really, religion as it exists today is an inevitability.