Hans Urs von Balthasar was one of the most influential Catholic theologians of the 20th century. He was born in Switzerland in 1905, joined the Jesuits in 1928 and was ordained as a Catholic priest in 1936. In 1950, though, he left the Jesuits, believing that God had called him to found a secular order of lay people. Because he'd left the Jesuits, he was banned from teaching in any of the Catholic universities, and he struggled to support himself by going on lecture tours. He gradually became more respected, though, and in 1988, Pope John Paul II asked him to be a cardinal. Unfortunately, however, he died before he was able to accept the offer.
One of the key relationships of Balthasar's life was with a woman called Adrienne von Speyr. Originally a Protestant, she converted to Catholicism partly due to Balthasar's influence. She had apparently experienced visions since she was a child, but afterwards began to have enormous numbers of visions, and other mystical experiences including stigmatisation (spontaneous pain or bleeding from which correspond to the wounds of Jesus. Cf. Francis of Assisi and the X-Files), and miracles. Between 1941 and 1965, every Easter she went into a trance from Good Friday until Easter morning, reliving the Passion of Jesus and experiencing a descent into hell with him. All pretty weird, no? Some of the content of the visions was pretty strange too, not least what they communicated about masculinity and femininity (sometimes coming dangerously close to describing God as divine rapist, which has been a bit passé since the death of Greek paganism).
Yet these visions were enormously influential on Balthasar. He described his and von Speyr's work as two halves of one whole, said that his work could not be properly understood without hers, and was reluctant to expose her work to criticism. The way he quotes her in some of his work resembles the way that fundamentalists quote the Bible, and her influence can be seen in many of his key concepts. All a bit strange, and problematic when you consider that Balthasar has been hugely influential on mainstream Catholic doctrine.
One of the issues Balthasar wanted to address was the question of why theology had become so boring. Apparently whilst studying Thomas Aquinas, he found his lecturers so dull that he would stuff his ears and read more racy material: Augustine and the early Church Fathers (hell, yeah). He though that by losing a sense of the beauty of God, theologians had missed the point and reduced theology to something dull and lifeless. He thought that the glory of God should be at the heart of theology, and wanted to build his whole theology around love: the glory of God, the essence of Truth, Beauty, and Goodness. Balthasar's magnum opus was the trilogy Herrlichkeit ("The Glory of the Lord"), Theodramatik, and Theologik.