The glory of God is a person fully alive," said the second-century theologian Irenaeus. Sadly, that description does not reflect the image many people have of modern Christians. Rightly or wrongly, they see us rather as restrained, uptight, repressed—people less likely to celebrate vitality than to wag our fingers in disapproval.

"What made you so negative against Christianity?" a friend once asked Friedrich Nietzsche. "I never saw the members of my father's church enjoying themselves," he replied. Where did Christians get the reputation as life-squelchers instead of life-enhancers? Jesus himself promised, "I am come that they might have life, and that they might have it more abundantly." What keeps us from realizing that abundant life?

In some believers, unhealthy family or church backgrounds may have a stifling effect. Adult Children of Alcoholics, an organization that works with families afflicted by alcoholism, identifies three coping mechanisms children learn in order to survive a dysfunctional setting: Don't Talk, Don't Trust, and Don't Feel. Christian counselors tell me that troubled Christians tend to operate by the same rules in relating to God. Emerging from a strict upbringing, or feeling disillusioned by some aspect of the Christian life, they squelch passion and fall back on a guarded, cautious faith. Fearful, they find a haven among people who think like they do, in a "safe" environment withdrawn from the world.

Of course, the church also includes a long tradition of mystics and monastics who viewed the world and its pleasures with open suspicion. John of the Cross advised believers to mortify all joy and hope, to turn "Not to what most pleases, but to what disgusts," and to "Despise yourself, and wish that others ...