During his career he was attracted to religious life, and he retired to become a monk. He retired around 628 to a hermitage at a mountain site in his domains in the Vosges. His friend Romaric, whose parents had been killed by Brunhilda, had preceded him to the mountains around 613, and together with Amatus had already established Remiremont Abbey there. After the death of Chlothachar in 629, Arnulf settled near Habendum, where he died some time between 643 and 647. He was buried at Remiremont.
Arnulf was canonized as a saint by the Roman Catholic Church. In iconography he is portrayed with a pastoral staff in his hand.
The Legend of the Beer Mug
It was July 642 and very hot when the parishioners of Metz went to Remiremont to recover the remains of their former bishop. They had little to drink and the terrain was inhospitable. At the point when the exhausted procession was about to leave Champigneulles, one of the parishioners, Duc Notto, prayed “By his powerful intercession the Blessed Arnold will bring us what we lack.” Immediately the small remnant of beer at the bottom of a pot multiplied in such amounts that the pilgrims’ thirst was quenched and they had enough to enjoy the next evening when they arrived in Metz.