The OP couldn't be much more overly simplistic than it is.
Religious belief is as old as humanity. It can be seen in the discovery of Gobekli Tepe, which predates written history by a pretty fair margin. Religion goes far further and is far more complex a societal mechanism than such a statement could begin to grasp. Ask an anthropologist about religion and see if you get such a simplistic view.
Even the most advanced civilizations of Antiquity had their pantheons and included the metaphysical with the physical in their learning and knowledge, i.e. the Greeks, the Mayans, the Romans, the Egyptians, the Incans, etc., some of which separated by vast oceans and having absolutely no influence over one another, yet they all had it. Spiritual belief/religion is a part of our DNA, partner.
But yeah, sure, religion is nothing more than a crutch. What an observation.
Well, it turns out that it is.
Religion is all about answering that pesky question "What happens when a Monkey dies?"
10,000 years of written history later and the Monkeys are no closer to an answer... perhaps it would be best left as a question.