With Discourse of Miracles and part of A Third Letter Concerning Toleration.

This classic work, first published in 1675, inaugurated the movement in Germany called Pietism. In it a young pastor, born and raised during the devastating Thirty Years War, voiced a plea for reform of the church which made the author and his proposals famous. A lifelong friend of the philosopher Leibnitz, Spener was an important influence in the life of the next leader of German Pietism, August Herman Francke. He was also a sponsor at the baptism of Nicholas Zinzendorf, founder of the Moravian Church, whose members played a crucial role in the life of John Wesley.

Upon no other View do I make a Dedication of this Discourse to your Lordship, then to submit it to your acute Judgment, expecting soon to hear of your Approbation or Dislike of it. If it so happen, that you highly approve of it, I beg of you to be sparing of your Commendations, least I should be puff'd up with them. In my Moderator, some Expressions dropt from my Pen about the Miracles of our Saviour, which, for want of Illustration then, gave your Lordship some Offence, and brought upon me more Trouble: But, having now fully and clearly explain'd my self out of the Fathers, I hope you'll be reconciled to me; and as you are a Lover of Truth, will, against Interest and Prejudice, yield to the Force of it. Whether your Prosecution of me, for the Moderator, was just and reasonable, I'll not dispute here, having already expostulated that Matter with you in several Letters, to which you would not condescend to give me any Answer. For what Reason you was silent, is best known to your self. But, in my own Vindication, I hope, I may publish without Offence, that your taking me for an Infidel, was such a Mistake as I thought no Scholar could have made; and the Injury done to my Reputation and low Fortunes, by the Prosecution, so considerable, that the least I expected from your Lordship, was a courteous Excuse, if not an ample Compensation, for it. As to the Expediency of prosecuting Infidels for their Writings (in whose Cause I am the farthest of any Man from being engaged) I will here say nothing. The Argument, pro and con, has already, by one or other, been copiously handled. And I don't know but I might be, with your Lordship, on the persecuting side of the Question; but that it looks as if a Man was distrustful of the Truth of Christianity, and conscious of his own Inability to defend it; or he would leave that good Cause to God himself and the Sword of the Spirit, without calling upon the Civil Magistrate for his Aid and Assistance. That scurvy Writer of the Scheme of literal Prophecy, &c. which your Lordship must have heard of, would insinuate, that they are only atheistical Priests, who, for fear of their Interests in the Church, set Persecutions on foot: But after your Lordship has publish'd a strenuous Defence of Christianity to the Purpose of our present Controversy, I'll have no such Suspicions of you. Your Lordship's persecuting (or, if you will, prosecuting) Humour, is reputedly all pure Zeal for God's Glory; and, with all my Heart, let it be so accounted, whether it be according to Knowledge or not. Against Popery and Infidelity you are all Ardency! Who does not commend you? Who can question the Sincerity of the Zeal of a Protestant Bishop, and of a Protestant Clergy, when they persecute the Enemies of their Church, that considers their own Steadiness to Principles against Interest, under all Changes, since the Reformation; and their Abhorrence of Extortion upon the People, for the Duties of their Function, in and about this City. Such Honesty and Constancy in their Profession, is a Proof of the Integrity of their Hearts, or I know not where to find one.