The phrase, "I'm spiritual, not religious" is commonly heard today. Yet, as Van Zeller points out in Approach to Spirituality, there is no spirituality without true faith, and there can be no faith without true religion. He demonstrates the necessity of a life truly conformed to God, particularly through prayer, in order for spirituality to have any root or effect. Genuine spirituality is not a vague ideal, but a practical, well-marked path to holiness, born out of faith in a God who is reality itself.

Exploring themes such as the fundamentals of prayer, its necessity for all, and its practical forms, Van Zeller cements the crucial foundations and maps tried-and-true paths in the spiritual life. While everyone desires a rich interior life marked by the heights and depths of union with God in love, a soul only progresses with the humble gift of faith: faith in a God who has come close and related to each individual. Therein Van Zeller reveals the true approach to spirituality, of which "the primary condition then is a belief in the interpersonal relationship between the Christian and Christ. Before you can get anywhere in the spiritual life you have to be convinced that such a relationship is possible and that it is open to you."