Joseph Müller was born on 19 August 1894 at Salmünster in Hesse, the youngest of the seven children of Damian Müller, the village cantor and schoolmaster, and his wife Augusta. He grew up in a household where faith, music and learning were woven together, completed his secondary studies and took his Abitur, and then volunteered for service in the First World War. At the front he was gravely wounded, and the injury marked his health for the rest of his life.
In February 1919, still convalescing from the war, he resolved to give himself to God as a priest, as two of his brothers had done. Because his home Diocese of Fulda then had more candidates than parishes to give them, he applied together with his brother Oskar to the Diocese of Hildesheim, where Catholics lived scattered in diaspora and priests were badly needed. He studied theology at the University of Münster, entered the Hildesheim seminary on 1 March 1921, and on 11 March 1922 he and his brother were ordained in Hildesheim Cathedral by Bishop Joseph Ernst.
His first assignment was as chaplain in Duderstadt. Drawn to the religious life, in April 1924 he entered the Franciscan friary of Frauenberg at Fulda, but his weak health forced him to leave the order that same autumn. Returning as a diocesan priest, he served as chaplain in Gehrden near Hanover, Hann. Münden, Celle, Blumenthal near Bremen, and from August 1926 in Wolfenbüttel, from where he also cared for the Catholics of Thiede. In 1931 he received his first parish, St. Benno in Bad Lauterberg in the Harz, with responsibility also for Sankt Andreasberg and Braunlage. In 1934 he became pastor of St. Boniface in Süpplingen, and in October 1937 of Saints Peter and Paul in Heiningen. After a serious operation had further weakened him, at his own request he was appointed on 1 August 1943 to the small parish of Saints Cosmas and Damian in Groß Düngen near Hildesheim.
War wounds and chronic illness left him physically limited, yet everyone who knew him spoke of his energy and courage. He was a stirring preacher who could reach even those who rarely came to church, and he was loved for the human warmth he showed to all. From his earliest years as a chaplain he poured himself into work with the young, and he made the care of apprentices and journeymen, after the mind of Blessed Adolph Kolping, a special apostolate. At Bad Lauterberg he persuaded the Sisters of Charity of St. Vincent to convert part of the veranda of their St. Benno sanatorium into a room for young people. Already in the years of the Weimar Republic his sermons and parish lectures warned urgently against the rising tide of National Socialism.
When the Nazis seized power in 1933, Father Müller did not soften a single word. He wished above all to protect the young from the ideology of the new rulers; as pastor in Heiningen he organized the resistance of families against the closing of the local school. For this he was shadowed constantly by the Gestapo, denounced and spied upon by local party men; his sermons, his services and his every activity were watched.
Shortly after his arrival in Groß Düngen, in early August 1943, he spoke openly to the local Nazi group leader of his anxiety over the state of the country. A few days later, visiting that man's sick father, he told a political joke then circulating: a dying soldier asks the nurse for whom he is giving his life; she brings him a picture of the Führer and lays it at his right hand; when he says he belongs to the air force, she lays a picture of Reich Marshal Göring at his left; and the soldier says, "Now I die like Christ." The joke became the pretext for denouncing the troublesome priest. On 17 August 1943 he was interrogated by the Hildesheim Gestapo and on 6 September taken into custody, accused of having compared Hitler and Göring with the two thieves crucified beside Jesus. His broken health won him a temporary release.
At the insistence of the local party group, which appealed to the People's Court in Berlin, he was arrested again on 11 May 1944 and on 15 May taken to the remand prison in Berlin-Moabit. Under every kind of interrogation he steadfastly refused to name the man who had told him the joke. From prison he wrote to his bishop words that reveal the whole man: "For the present I can no longer work as a pastor, but now I will walk with Christ the road that is also of pastoral value, the road of suffering and of prayer. I do not yet know the way God wills to lead me in the future, but whatever it may be and wherever, it will not find in me a figure of misery. Yet I too need above all the help from above. It will not fail me — of that I am certain." When his brothers and his bishop, Joseph Godehard Machens, visited him two weeks later, they found a poor prisoner in patched prison clothing, worn down and crushed in spirit — and still holding fast.
On 28 July 1944 he was given a show trial before the People's Court. Roland Freisler accused him of having, as a youth chaplain, hindered and frustrated the work of the state youth organization, calling it high treason, sabotage and the undermining of state authority for a "cleric" to estrange the young from the Führer. Witnesses for the defense from Groß Düngen were never heard. He was sentenced to death for Wehrkraftzersetzung, the undermining of military morale. On 11 September 1944 Joseph Müller was executed by guillotine in the prison of Brandenburg-Görden. Freisler's court afterward sent his family a bill for the execution.
Contrary to local custom, the authorities forbade the tolling of the death bell in Groß Düngen for the executed pastor. When the Nazi regime fell, the first act of the village was to ring that bell. His ashes, first buried in the municipal cemetery at Brandenburg, were brought home to Groß Düngen in November 1945, fulfilling his written wish to rest where his bishop's call had last sent him as priest and pastor, beneath a cross bearing the image of the Savior, with the confession: "Credo in vitam aeternam" — I believe in life everlasting. His prison writings and letters are treasured as a moving Christian testimony.
Every year since the end of the war, on 11 September at one o'clock, the death bell of the parish church in Groß Düngen is tolled in his memory, as are the bells of his native Salmünster. In 1999 he was entered into the first edition of the German Martyrology of the Twentieth Century published for the German Bishops' Conference. Streets, a primary school, and parish halls in Hildesheim, Bad Salzdetfurth, Bad Soden-Salmünster, Wolfenbüttel, Salzgitter-Thiede, Bad Lauterberg, Duderstadt and Delligsen bear his name. The unjust sentence was formally annulled by the Berlin public prosecutor only in June 2014; some three hundred people gathered that year for the seventieth anniversary of his death. In May 2016 the Diocese of Hildesheim opened his cause of martyrdom.
May Blessed Joseph Müller obtain for us the courage to speak the truth plainly when silence would be safer, and to protect the young entrusted to us at any cost.