What would life be like if God did not exist? If we found that such a life would be quite unlike our own lives as actually lived, that would be a pretty strong indication that atheism is false; that it disagrees with reality as we actually encounter it. Since God, if he exists, is by far – infinitely far – the biggest most important thing there is, our decision about whether he exists is the most important and far-reaching decision we can make in life. Thus if God exists, and we approached the question of his existence in the wrong spirit, it would be the worst mistake of our lives; as if we had spat on the Good King, but far, far worse; for the King in question would be the King of Everything.
It behooves us to approach the question in the right frame of mind, so that we are less likely to err in our thinking.
Part of approaching the question in the right spirit is being honest with ourselves about how things would be if God did not exist. To begin with a closed mind, or to beg the question and insist that nothing could be different if God did not exist, would be to cheat the whole project. But it is crucial to recognize that, in cheating the project, we would be hurting only ourselves.
What are the aspects of life that we are going to find most indicative? What, that is, are the things that might be quite different for us if there were no God? Well, what are the basic features of our lives?