Religion comes in two dimensions: religion of the Self, and religion of the ego. I use these two terms in a quasi-Jungian sense.
Religion of the Self is difficult and challenging. Since you cannot be born into it, you have to work really hard to make any progress in religion of the Self. The more you progress, the more humble you are.
Religion of the ego, on the other hand, is rather easy to acquire; very often, you are simply born into it. This flavor of religion feeds the ego, sometimes inflating it to enormous sizes. The more you identify with religion of the ego, the more superior you feel over other mortals.
Religion of the Self is the vertical dimension of religion. In the vertical dimension, truth is an attribute of the person, not an attribute of a particular religion. You are concerned with questions like “Am I truly religious?” and “How true am I in my religious life?”
Religion of the ego is the horizontal dimension of religion. In the horizontal dimension, truth is an attribute of a particular religion, not an attribute of the person. You are concerned with questions like “Which religion is true?” and “If my religion is true, does this mean that all other religions are false?”
One talks about the vertical dimension of religion using the analog logic, the logic of less/more. In this dimension, some people are more religious than others; I may be less religious today than I was last week, and more religious the next week than I am now. In one moment there may be ecstatic joy and in a different moment one may fall in dark despair; one may feel constricted at one time and expanded at another time. The vertical dimension is all about change.
What Shakespeare said about the course of true love also applies to the course of one’s religious life in the vertical dimension: it never runs smooth. Indeed, this dimension is always fresh; there is never a dull moment in the life of the spirit. The heart is in permanent flux, and the boundaries between one inner state and another are not marked very clearly.
The horizontal dimension of religion, on the other hand, follows the digital logic, the logic of yes/no. As a result, when we are speaking of the horizontal dimension, we say that some people belong to this religion, others to another religion, and still others are associated with some third religion. In talking about the horizontal dimension, we say that you have either this religion or that. Boundaries between two religions are sharp and precise; you are either inside a given religious community or you are outside it. You can leave one religion and join another, but you cannot belong to two or three religions at the same time; this is logically impossible.
The horizontal dimension is about the ego; the ego has a strong need for identity, to belong, to be “somebody.” The ego loves structures and absolutes, and it can’t stand ambiguity and ambivalence. The significance of the horizontal dimension is primarily sociological, and secondarily psychological. By “having” a religion, or by “belonging to a religion,” we learn who we are: we are this, and you are that.
The vertical dimension is about the Self; the Self is capable of transcending all needs for particular identities such as those derived from gender, nationality, race, or religion. The Self thrives in ambiguity and ambivalence. The significance of the vertical dimension is primarily spiritual, and secondarily moral. In the vertical dimension, even the ego’s need for identity is not eliminated; it is turned into nourishment for the spirit.
To quote Wilfred Cantwell Smith, the difference we are dealing with here is the difference between noun and adjective. The vertical dimension is the realm of the adjective; the horizontal is the abode of the noun. The horizontal world of the noun is black-and-white; it is built on labels that we wear on the outside. In the horizontal dimension, when asked “Are you a Christian?” or “Are you a Muslim?” one may respond by a simple “yes” or “no.”
On the other hand, the vertical realm of the adjective is a dynamic kaleidoscope of innumerable colors and shades. In the vertical dimension, when asked “Are you Christian?” or “Are you Muslim?” one must hesitate and utter something along the lines of “I try, but I mostly fall short.”
The noun is from the ego; the adjective from the Self.