He attended the Hochschule für Musik Köln where he studied organ under Wolfgang Stockmeier and Michael Schneider and the harpsichord under Hugo Ruf.
After completing his studies in Cologne, he went to receive further education in Paris through a scholarship provided by the Government of France.
After working as a church musician for many years, Karius took the position as organist, cantor, and choral conductor at the Annakirche in Aachen in 1983.
He led the ensemble up until 2008 during which time he toured with the choir throughout Western and Eastern Europe, Canada, Israel, and Lebanon.
He has also made several radio appearances and CD recordings both as an organist and with the Aachener Bachverein for Erato, SFPP, Schwann and Electrola.