For another person their god is alcohol, or sex, or money, or material things, or education, or status, or power, or a prestigious title, position, degrees, music, sports, success, ownership, etc. There's not enough security. We reveal who our god is when any of these substitutes make the decisions for us about how to use our time, talents, and treasure. Looking for their own private personal individual god, people escape into witchcraft, astrology, reincarnation, and countless cults. The result is hopeless living and hopelessness regarding the future.
Nothing matters because there is nothing real to hold on to.
All of this is foundational to understanding how the modern mind and its way of thinking has been developed. It is faith with a foundation. It is faith rooted in the God of the Bible, not the god of one's imagination. The God of the Bible is the only rational answer, the only sure answer to our needs. Only the God who created mankind can ever satisfy mankind.