Religion is not a special function of man’s spiritual life, but it is the dimension of depth in all of its functions. The assertion has far-reaching conequences for the interpretation of religion… (5-6)
In this situation, without a home, without a place in which to dwell, religion suddenly realizes that it does not need such a place, that it does not need to seek for a home. It is at home everywhere, namely, in the depth of all functions of man’s spiritual life. Teligion is the dimension of depth in all of them. Religion is the aspect of depth in the totality of the human spirit.
What does the metaphor depth mean? It means that the religious aspect point to that which is ultimate, infinite, unconditional in man’s spiritual life. Religion, in the largest and most basic sense of the word, is ultimate concern. And ultimate concern is manifest in all creative functions of the human spirit. It is manifest in the moral sphere as the unconditional seriousness of the moral demand. … Ultimate concern is manifest in the realm of knowledge as the passionate longing for ultimate reality. … Ultimate concern is manifest in the aesthetic function of the human spirit as the infinite desire to express ultimate meaning. … Religion is the substancee, the ground, and the depth of man’s spiritual life. (7-8)
Paul tillich. Religion as a Dimension in Man’s Spiritual Life. In: Ders. Theology of Culture. Ed. by Robert C. Kimball. Oxford Uiversity Press: New York, 1959.