In 1818, when Joseph Mohr is assigned to be the new assistant priest in Oberndorf, a small Austrian town near Salzburg, the young man is full of ideas and ideals. His passion to bring the church closer to the common people sets him on a collision course with his new superior, Father Nostler. When Mohr organizes a church choir that includes outcasts from the local tavern and performs in German instead of Latin, Nostler threatens him with disciplinary action. Their relationship further deteriorates when Maria a regular tavern patron, surprisingly joins the performance of the all-male church choir. As Mohr's initial successes start to crumble and his efforts backfire on him, he loses all hope and faces a trial of faith. The night before Christmas, Mohr has to decide if he will accept defeat and leave Oberndorf or embrace the true significance of the Holy Night.