The answer is not as clear-cut as it might seem. We may not believe in a Supreme Being. But does this mean we have no God? Here's a test. Simply ask yourself, "What do I worship? To what do I give extreme devotion, or intense love and admiration? What do I see as the supreme good?" Identify what this is in your life, and for all practical purposes you have found your "God." And this "God" will rule you and determine the course of your life just as if it were all-powerful.
Don't we see every day the good and bad effects of the billion-odd "gods" that mankind worship? Wherever we look we see people religiously devoted to some person, pursuit, ideal, or goal, and existentially speaking, it ism their "God." Whether or not we say we believe in a Supreme Being as such is secondary to our actual worship of the object of our desire and devotion.
On this pragmatic basis, there is no such thing as an atheist. Every human being is, in a mannger of speaking, religious, intensely devoted to what he believes to be good, or God. The self-declared atheist, agnostic, or unbeliever may be reluctant to admit that he has a form of worship. But one can never conclusively determine for himself whether or not there is an actual God while unaware of the implications of his own personal devotions. Worship of personal gods blinds us to any evidence there might be of a real God.
Wasn't this the problem Christ Jesus lamented? He once said, "This people's heart is waxed gross, and their ears are dull of hearing, and their eyes they have closed; lest at any time they should see with their eyes, and hear with their ears, and should understand with their heart, and should be converted, and I should heal them." n1
n1 Matthew 13:15;