Just as a candle cannot burn without fire, men cannot live without a spiritual life, Buddha.
Religion can be traced back to the dawn of human existence, and it plays an essential role in the life of billions of people around the world. Therefore, it is very important for everyone to have an overall knowledge about it regardless of whether or not you believe in God.
Religion is a social-cultural system of designated behaviors and practices, morals, worldviews, texts, sanctified places, prophecies, ethics, or organizations, that relates humanity to supernatural, transcendental, or spiritual elements (Religion, Wikipedia).
There are an estimated 10,000 distinct religions worldwide. “Worldwide, more than eight-in-ten people identify with a religious group. A comprehensive demographic study […] estimates that there are 5.8 billion religiously affiliated adults and children around the globe, representing 84% of the 2010 world population of 6.9 billion,” The Global Religious Landscape.
Moreover, Babies born to Muslims will begin to outnumber Christian births by 2035. Global atheism may be in decline due to irreligious countries having the lowest birth rates in the world and religious countries having higher birth rates in general (Atheism: Contemporary Numbers and Patterns, Phil Zuckerman).