The actual work of organizing the "indulgence-campaign" was put into the hands of John Tetzel, whose large experience in the selling of indulgences fitted him excellently for the post of Sub-commissioner. The indulgence-sellers acted under the commission of the Archbishop and the directions of Tetzel, who took personal charge of the enterprise. The preachers went from city to city, and during the time that they were preaching the indulgence in any given place, all other preaching was required to cease.[26] They held out the usual inducements to prospective buyers. The plenary nature of the indulgence was made especially prominent, and the people were eloquently exhorted that the purchase of indulgence-letters was better than all good works, that they were an insurance against the pains of hell and of purgatory, that they availed for all satisfactions, even in the case of the most heinous sins that could be conceived.[27] "Confessional letters" [28] were one of the forms of this indulgence. They gave their possessor permission to choose his own confessor, and entitled him to plenary remission once in his life, to absolution from sins normally reserved, etc. The indulgences for the dead were zealously proclaimed, and the duty of purchasing for departed souls release from the pains of purgatory was most urgently enjoined. So great was the power of the indulgence to alleviate the pains of purgatory, that the souls of the departed were said to pass into heaven the instant that the coins of the indulgence-buyer jinked in the money-box.[29] 4. Luther's Protest—The Theses were Luther's protest against the manner in which this indulgence was preached, and against the Use conception of the efficacy of indulgences which the people obtained from such preaching. They were not his first protest, however. In a sermon, preached July 37th, 1516,[30] he had issued a warning against the false idea that a man who had bought an indulgence was sure of salvation, and had declared the assertion that souls could be bought out of purgatory to be "a piece of temerity." His warnings were repeated in other sermons, preached October 31st, 1516, and February 14th, 1517.[31] The burden of these warnings is always the same: the indulgences lead men astray; they incite to fear of God's penalties and not to fear of sin; they encourage false hopes of salvation, and make light of the true condition of forgiveness, vis., sincere and genuine repentance.