Christianity asserts that every individual human being is going to live for ever, and this must be either true or false. Now there are a good many things which would not be worth bothering about if I were going to live only seventy years, but which I had better bother about very seriously if I am going to live for ever.
–C. S. Lewis
Moreover, if atheism is true, there is no moral accountability for one’s actions. Even if there were objective moral values and duties under naturalism, they are irrelevant because there is no moral accountability. If life ends at the grave, it makes no difference whether one lives as a Stalin or as a saint. As the Russian writer Fyodor Dostoyevsky rightly said: “If there is no immortality, then all things are permitted.”
–William Lane Craig