Spirit is the presence of what concerns us ultimately, the ground of our being and meaning.
Paul TillichOut of the element of participation follows the certainty of faith; out of the element of separation follows the doubt in faith. And each is essential for the nature of faith. Sometimes certainty conquers doubt, but it cannot eliminate doubt. The conquered of today may become the conqueror of tomorrow. Sometimes doubt conquers faith, but it still contains faith. Otherwise it would be indifference.
Paul TillichMan and nature belong together in their created glory – in their tragedy and in their salvation.
Paul TillichWhy does philosophy use concepts and why does faith use symbols if both try to express the same ultimate? The answer, of course, is that the relation to the ultimate is not the same in each case. The philosophical relation is in principle a detached description of the basic structure in which the ultimate manifests itself. The relation of faith is in principle an involved expression of concern about the meaning of the ultimate for the faithful.
Paul TillichI have given no definition of love. This is impossible, because there is no higher principle by which it could be defined. It is life itself in its actual unity. The forms and structures in which love embodies itself are the forms and structures in which love overcomes its self-destructive forces.
Paul Tillich