Rubuta ci gaba don wannan sakin layi - Bayan barin École Niedermeyer, an nada Fauré a matsayin mai kula da kayan aiki a Cocin Saint-Sauveur, a Rennes a Brittany. Ya dauki mukamin ne a watan Janairun 1866. A lokacin shekaru hudu a Rennes ya kara kudin shiga ta hanyar daukar dalibai masu zaman kansu, yana ba da "koyaswar piano da ba a iya lissafawa ba". A kan Saint-Saëns na yau da kullun ya ci gaba da yin rubutu, amma babu wani daga cikin ayyukansa daga wannan lokacin da ya tsira. Ya yi baƙin ciki a Rennes kuma yana da dangantaka mai ban sha'awa tare da firist na Ikklisiya, wanda ya yi shakka game da imani na addini na Fauré. An ga Fauré a kai a kai yana ɓoyewa a lokacin wa'azi don sigari, kuma a farkon 1870, lokacin da ya bayyana don yin wasa a Mass a ranar Lahadi ɗaya a cikin tufafinsa na yamma, bayan ya fita duk dare a ball, an nemi ya yi murabus. Kusan nan da nan, tare da taimakon Saint-Saëns mai hankali, ya sami mukamin mataimakin organist a cocin Notre-Dame de Clignancourt, a arewacin Paris. Ya zauna a can 'yan watanni kawai. Da barkewar Yaƙin Franco-Prussian a 1870 ya ba da kansa don aikin soja. Ya shiga cikin aikin don tayar da kewaye da Paris, kuma ya ga aikin a Le Bourget
, Champigny da kuma Créteil. An ba shi lambar yabo ta "Croix de Guerre".