Out 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 TillichSpirit is the presence of what concerns us ultimately, the ground of our being and meaning.
Paul TillichAll things and all people, so to speak, call on us with small or loud voices. They want us to listen. They want us to understand their intrinsic claims, their justice of being. But we can give it to them only through the love that listens.
Paul Tillich