There is a product of religion that outlived the religion that created it and remains a part of common knowledge of every educated person on Earth. It is the Great Pyramid of Giza. Constructed during the golden age of the Old Kingdom of Egypt, around 2560 BCE, it still stand, still being explored and researched and still subject to numerous scientific and pseudoscientific theories. There isn’t a person alive that does not know about the great pyramids.
Ancient Egypt was a textbook example of a theocracy, perhaps the most theocratic nation of the ancient times, with religion affecting everyday life of everyone from commoner to king. The ruler of the kingdom, the Pharaoh, was hailed as a descendant of a god (Bat/Hathor), was to be worshipped as a god (sometimes as an avatar of god Horus), and would join the ranks of gods or merge with god Osiris (becoming his avatar) after death, provided intricate and often labor-intensive provisions have been taken to arrange it, such as building a pyramid. Even though the building of the pyramids did not involve excessive forced labor and human suffering, as the builders were skilled and enthusiastic about their work, the nation’s economy was ruined by the great building projects of Old Kingdom, and it played no small part in its later demise amidst civil wars and famines. Only the pyramids stand as monuments to the amounts of effort the people can be willing to spend when acting upon their religious knowledge.