§ 21. It consisted principally of the matter which he had introduced in a course of practical sermons previously delivered by him on week-days. It attracted great attention, and was rapidly circulated throughout Germany. The modest and retiring author, without expecting such a result, at once became a celebrity. Nevertheless, new trials now commenced. An envious feeling seems to have been engendered in the hearts of several of his colleagues in the “ministerium” of the city, when they noticed the honor which the author had undesignedly gained. Perhaps, too, the controversial spirit of the times, and the jealousy of good men respecting the faith, which was assailed on all sides—by Papists, Calvinists, Unitarians, fanatics, etc.,—may have led them to scrutinize the book with too suspicious eyes. All held firmly to the Gospel doctrine of Justification by faith alone, without works. Now, when they found that Arndt insisted with such earnestness on the evidences of faith, as furnished by a holy life, they were morbidly affected, and apprehended that the doctrine of justification by faith _alone_, which their bitter enemies, the Papists, denounced, had not been guarded with sufficient care by Arndt. Other expressions, again, which they did not interpret impartially, led them to fear that he was introducing mysticism and other morbid religious systems into the Church. The reproaches which he was compelled to hear, deterred him for some time from fulfilling his promise of adding three other “Books” to Book I. The complete work may be regarded as consisting of _Four_ Books, as published in 1609. At a considerably later period a fifth, and then a sixth book, were added. The former was designed as an explanation and recapitulation of the Four Books, and the latter, consisting in part of letters addressed to various eminent theologians, besides having the same object in view, was intended also to defend the doctrinal and ethical positions assumed in the Four Books. As they partake of the nature of an appendix, and refer, to some extent, to misunderstandings belonging to an earlier age, the Latin versions omit them, and this example was followed by the English translator.