Karl Rahner believed that the fulfillment of human existence consists in receiving God's self-communication, and that the human being is actually constituted by this divine self-communication. Karl Rahner also often preferred the term "mystery" to that of God."He identifies the God of Absolute Being as Absolute Mystery.

MESSAGE - Quote from Karl Rahner-
“So You haven’t really sent me away from You, after all. When You assigned me the task of going out among men, You were only repeating to me Your one and only commandment: to find my way home to You in love. All care of souls is ultimately possible only in union with You, only in the love that binds me to You and thus makes me Your companion in finding a path to the hearts of men.