Luther, Doctor Martin—1483-1546—the great instrument of God, father and master of the art of hymn-writing, and of German poetry. ‘Ach Gott, vom Himmel sieh darein,’ here selected, is a free paraphrase of the 12th Psalm, a call of the Church, founded on God’s word, for aid and protection against those who despised and corrupted it, written in 1523.