A psychologist tests Freud's claims that faith is a form of wishful thinking and belief in God a consoling illusion. Is faith simply a form of wishful thinking? Is belief in God merely a consoling illusion? So argued Sigmund Freud in The Future of an Illusion. And the force of Freud's argument continues to be felt as it features prominently among critics of religion such as the New Atheists. But was Freud right? Until now, few have directly examined the plausibility of Freud's argument. But here, in a groundbreaking analysis inspired by the religious types described by William James in his seminal The Varieties of Religious Experience, Richard Beck explores the motivational dynamics among "summer Christians" and "winter Christians." Further, across a variety of laboratory studies, Beck examines how Christians variously engage with art (exploring what Beck has dubbed "The Thomas Kinkade Effect"), doctrine (from the Incarnation to beliefs regarding the activity of the devil), and religious difference in a pluralistic world. In each instance, Beck analyzes the underlying motivations of the religious types, sifting through the varieties and illusions of religious experience.The Authenticity of Faith presents a radical "New Apologetics," an attempt to move beyond contentious philosophical and theological disputes to examine the scientific merits of Freud's critique of faith. Here is an unlikely journey the scientific search for an authentic faith; the outcome is sure to inspire reflection, conversation, and debate among believers and skeptics alike.