In 1675 Spener published his great work, Pia Desideria. Here he laid down his platform: That the word of God should be brought home to the popular heart; that laymen, when capable and pious, should act as preachers, thus becoming a valuable ally of the ministry; that deep love and practical piety are a necessity to every preacher; that kindness, moderation, and an effort to convince should be observed toward theological opponents; that great efforts should be made to have worthy and divinely-called young men properly instructed for the ministry; and that all preachers should urge upon the people the importance of faith and its fruits. This book was the foundation of Spener's greatest influence and also of the strongest opposition with which he met. As long as he taught in private he escaped all general antagonism; but on the publication of his work he became the mark of envy, formalism, and high-churchism.

After he was invited to Dresden in 1686, the state church indicated a decided disapprobation of his measures. He incurred the displeasure of the Elector by his fearless preaching and novel course of educating the young. His teaching of the masses drew upon him the charge that "a court-preacher was invited to Dresden, but behold, nothing but a school teacher!" He deemed it his duty to accept the invitation of Frederic of Brandenburg to make Berlin his residence, where, in 1705, he ended his days, after a life of remarkable usefulness but of unusual strife.

It would be a pleasure to linger a while in the beautiful scenes which Spener's life affords us. Endowed with the most childlike nature, he was nevertheless a lion in contest. And yet who will find any bitterness in his words; where does he wax angry against his opponent? He did not shun controversy, because his mission demanded it; but no man loved peace more than Spener. His mind was always calm; and it was his lifelong aim to "do no sin." His enemies,—among whom we must not forget that he had a Schelwig, a Carpzov, an Alberti, and a whole Wittenberg Faculty,—never denied his amiable disposition; and it was one of his expressions in late life that "all the attacks of his enemies had never afflicted him with but one sleepless night." It was his personal character that went almost as far as his various writings to infuse practical piety into the church. He was respected by the great and good throughout the land. Crowned heads from distant parts of the Continent wrote to him, asking his advice on ecclesiastical questions. He was one of those men who, like Luther, Wesley, and others, was not blind to the great service of an extensive correspondence. He answered six hundred and twenty-two letters during one year, and at the end of that time there lay three hundred unanswered upon his table. His activity in composition knew no bounds. For many years of his life he was a member of the Consistory, and was engaged in its sessions from eight o'clock in the morning until seven in the evening. But still he found time, according to Canstein, to publish seven folio volumes, sixty-three quartos, seven octavos, and forty-six duodecimos; besides very many introductions and prefaces to the works of friends and admirers, and republications of practical books suited to the times and the cause he was serving. After his death his enemies did all in their power to cast reproach upon his name. They even maligned his moral character, which had hitherto stood above reproach. It was a grave question at the hostile universities whether the term Beatus Spener could be used of him. Professor Teck, of Rostock, published a work On the Happiness of those who die in the Lord, in which he decided that heaven will open its gates sometimes to the extremely impious who die without any external mark of repentance, and also to those who die in gross sin; but not to such a man as Spener.

The University of Halle was founded for the avowed purpose of promoting personal piety, Scriptural knowledge, and practical preaching throughout the land. It had already been a place of instruction, but not of theological training. The theological faculty was composed of Francke, Anton, and Breithaupt. These men were deeply imbued with the fervid zeal of Spener, and set themselves to work to improve and continue what he had inaugurated. The field was ample, but the task was arduous. While Spener lived at Dresden, Francke, who taught at Leipsic, enjoyed a brief personal intercourse with him, and became thoroughly animated with his spirit. On his return to Leipsic, he commenced exegetical lectures on various parts of the Bible, and instituted Collegia Pietatis for such students as felt disposed to attend them. So great was the increase of attendance, both at the lectures and also at the meetings, that Francke was suspended and Pietism forbidden. It was, therefore, with a wounded and injured spirit that he availed himself of the privilege afforded in the new seat of learning.

Francke was naturally an impulsive man, and his ardent temperament led him sometimes into unintended vagaries. An extravagance of his once caused Spener to remark, that "his friends gave him more trouble than all his enemies." But he was not more erroneous than most men of the same type of character; and there is not a real moral or intellectual blemish upon his reputation. His aim was fixed when he commenced to teach at Halle; and he prosecuted it with undivided assiduity until the close of his useful life. The story of his conversion is beautifully told in his own language. Like Chalmers, he was a minister to others before his own heart was changed. He was about to preach from the words, "But these are written, that ye might believe that Jesus is the Christ, the Son of God; and that believing ye might have life through his name." He says: "My whole former life came before my eyes just as one sees a whole city from a lofty spire. At first it seemed as if I could number all my sins; but soon there opened the great fountain of them—my own blind unbelief, which had so long deceived me; I was terrified with my lost condition, and wondered if God were merciful enough to bless me. I kneeled down and prayed. All doubt vanished; I was assured in my own heart of the grace of God in Christ. Now I know him, not alone as my God but as my Father. All melancholy and unrest vanished, and I was so overcome with joy, that from the fullness of my heart I could praise my Saviour. With great sorrow I had kneeled; but with wonderful ecstacy I had risen up. It seemed to me as if my whole previous life had been a deep sleep, as if I had only been dreaming, and now for the first time had waked up. I was convinced that the whole world, with all its temporal joy, could not kindle up such pleasure in my breast."

A few days afterwards he preached from the same text as before. The sermon was the first real one that he had preached. Henceforth his heart was in the work for which God had chosen him.

He preached in Halle statedly, for, in addition to the duties of the professor's chair, he was pastor of a church. His ministrations in the pulpit became extremely popular and attractive. Naturally eloquent, he won the masses to his ministry; and by his forcible presentation of truth he molded them into his own methods of faith and thought. Nor was he less zealous or successful in his theological lectures. He commenced them in 1698, by a course on the Introduction to the Old Testament, concluding with a second one on the New Testament.

In 1712, he published his Hermeneutical Lectures, containing his comments on sections and books of Scripture, particularly on the Psalms and the Gospel of John. In his early life he had observed the dearth of lectures on the Scriptures; and he accordingly applied himself to remedy the evil. His principles of instruction were, first, that the student be converted before he be trained for the ministry, otherwise his theology would be merely a sacred philosophy—philosophia de rebus sacris; second, that he be thoroughly taught in the Bible, for "a theologian is born in the Scriptures." His Method of Theological Study produced a profound impression, and was the means of regenerating the prevailing system of theological instruction at the universities.

But Francke is chiefly known to the present generation by his foundation of the Orphan House at Halle. This institution was the outgrowth of his truly practical and beneficent character; and from his day to the present, it has stood a monument of his strong faith and great humanity. Its origin was entirely providential. It was already a custom in Halle for the poor to convene every week at a stated time, and receive the alms which had been contributed for their support. Francke saw their weekly gatherings, and resolved to improve the occasion by religious teaching. But their children were also ignorant, and there was no hope that the parents would be able to educate them. So he resolved to do something also in this direction, and secured some money for this purpose. But yet the parents did not thus apply it; whereupon he placed a box in his own dwelling, that all who visited him might contribute. He knew that then he would have the personal distribution of such funds. During three months one person deposited four thalers and sixteen groschen; when Francke exclaimed, "That is a noble thing—something good must be established—with this money I will found a school." Two thalers were spent for twenty-seven books; but the children brought back only four out of the whole number that they had taken home. New books were bought, and henceforth it was required that they be left in the room. At first Francke's own study was the book depository and school-room; but in a short time his pupils so greatly increased that he hired adjacent accommodations. Voluntary contributions came in freely; new buildings were erected, and teachers provided; and before the death of the founder, the enterprise had grown into a mammoth institution, celebrated throughout Europe, and scattering the seeds of truth into all lands.[26] It became a living proof that Pietism was not only able to combat the religious errors of the times but also to grapple with the grave wants of common life. Is not that a good and safe theology, which, in addition to teaching truth, can also clothe the naked and feed the hungry? Francke's prayer, so often offered in some secluded corner of the field or the woods, was answered even before his departure from labor to reward; "Lord, give me children as plenteous as the dew of the morning; as the sand upon the sea-shore; as the stars in the heavens; so numerous that I cannot number them!"