Yep Dietrich Bonhoeffer
He is one of the best writers on Christianity there is. His books are not for the new Christian generally. His thoughts are profound and deep. He was truly a man of God. He challenges your understanding and takes it to a new level.
Was executed:
The camp doctor who witnessed the execution wrote: “I saw Pastor Bonhoeffer ... kneeling on the floor praying fervently to God. I was most deeply moved by the way this lovable man prayed, so devout and so certain that God heard his prayer. At the place of execution, he again said a short prayer and then climbed the few steps to the gallows, brave and composed. His death ensued after a few seconds. In the almost fifty years that I worked as a doctor, I have hardly ever seen a man die so entirely submissive to the will of God.”
He wouldn't understand someone calling themselves a "Social Christian"....