Edvard was brought up in a religious Lutheran home but biographers say his faith collapsed at some point during the 1880s, after he came in contact with the radical circles of the Kristiania bohemians founded by Hans Jasger (munch portrait seen here) who in particular must have played a decisive role in this.
Soon afterwards he began a relationship with a married woman, having come to believe monogamy was only for the bourgeois. This was the start of serial “love” affairs, including a particularly frenzied one with a cousin which his friends said drove him deeper into alcoholism, “near to insanity,” and by Munch’s own admission residual “fears of damnation”.
All of this brought great sorrow to his very religious father.
Meanwhile Munch drifted off into spiritualism and pantheism, and his famous paintings during this period exude metaphysical interests coupled with anxiety to the end, also the conflict between family piety and decadence. He was not unaware of evil in the world (his ominous famous painting The Murderer tells eloquently).
Jasger taught his boheminan circles nine commandments (only) and that “sexuality should become unrefuted and unrestricted in relationships, maintaining the traditional values of marriage and social class did encroach on such an appetite quite unnecessarily. His idea called for a few catalysts; Jæger cajoled that the institution of marriage should be necessarily abolished, and that full inter-class freedoms of what intimacies and romantic expressions may be conveyed are allowed unconditionally.” [Wiki]
Munch painted his famous Golgotha (seen above) in 1900, but also began to read Nietzsche and was well aware of the new “evolution” revival which also helped maintain his distance from any formal Christianity or faith. But he was never quite comfortable, metaphysical questions still occupied him, and he was also getting more realistic about the limits of his own body for mania, alcohol and women.
After another serious breakdown in 1908 he largely broke from his bohemian friends and settled down to a better, if not entirely monogamous, life in various country houses in Norway for the second half of his life as a Master to students who eagerly gathered around him. He died in Oslo in 1944, hopefully in some peace.
Source of facts:
Alf Boe [Alf Bøe], Edvard Munch, Rizzoli: New York, NY (1989), pages 28-30, and Wikipedia