After serving as chaplain at St. Valentin, he was sent to Neukloster Priory in Wiener Neustadt, where he co-founded the Sodality of Our Lady.

[citation needed] In the spring of 1945, Wiener Neustadt was subject to heavy air raids by the Allied Forces, killing many people.

During Holy Week, as the Red Army advanced on Wiener Neustadt, Rabensteiner and the few remaining monks celebrated Mass in the sacristy or the basement of the already heavily damaged monastery.

On Easter Monday, 2 April, the Red Army entered the city after heavy artillery bombardment and fights with the remaining German forces.

Rabensteiner removed the bodies of fallen German soldiers from the street beside the monastery to prevent them being run over by Russian tanks.