In everything I’ve read about Hitler and WWII I’ve never seen any reference to him even attending a Catholic church, much less practicing the faith.
In 1937, Pius XI published the Encyclical Mit Brennender Sorge, stating that Catholics must never be anti-Semite.
On March 14, 1937, before it was fashionable to denounce the German Führer as a villain and long before the creation of the concentration camps and the gas chambers, Pius XI, ably seconded by his Secretary of State, wrote the Encyclical Mit Brennender Sorge meaning with burning anxiety. It dealt with the nazi threat to racial minorities and specifically the Jews addressing the Encyclical directly to the German people. The Encyclical exhorted that Catholics must never be anti-Semitic because we are all Semites spiritually and ought to hold the Jewish people in high regard accordingly. The Encyclical exposed to the world the III Reichs persecution of the Catholic Church as well as the incompatibility between the principles of the National Socialism and those of the Catholic faith. The German government prohibited the entrance of the Encyclical to the country and it became necessary to smuggle it into Germany under the nose of the ruthless Gestapo. On Sunday March 21, The Encyclical was read from 12,000 Catholic pulpits across Germany. As a result, the Nazis campaign of innuendoes against The Church as well as the persecution of Catholics worsened.
The German Catholic hierarchy thanked Pope Pius XI for the letter, which strongly condemned both, racism and anti-Semitism. The Pope pointed to Cardinal Pacelli (later elected Pope Pius XII) saying that it was he who had been responsible for the Encyclical. It was the Secretary of State, who asked the German Cardinal Faulhaber to submit a draft text, which he amended carefully. Pacelli also bore the burden of its defense when the Encyclical was the subject of strong German diplomatic protests; he did so personally, not by delegation.
I agree that Hitler excommunicated himself but could you provide a reference showing Hitler to have been a member, or associate of Los von Rom?