WHEN I first reprinted the present treatise in a separate form from the theol. Stud. und Krit., it was specially designed for the use of my own pupils and of young theologians in general. I desired to point out to them the way in which I had myself been led to a vital interest in Christianity, and hoped thus to contribute to the establishment of their faith, to encourage them in their studies, and to increase their delight in their high and holy calling. Nor have my hopes been disappointed. But besides the circle for which it was at first designed, this little work has passed into the hands of both theological and general readers, and has gained such acceptance that repeated editions have been necessary.