Christian and Muslim apologists excuse the history of their religion by saying most religions are violent. This is simply false. Most religions are not violent. Christianity and its progeny — Islam — were built on Roman Imperialism. I would argue that Communism, as reinvented by Stalin, had the same fault.
For that matter, only a few religions have ever even been concerned with morality in any form. While Hammarubi may have seen his gods as endorsing the legal codes of Babylon, following the law was not a precept of divine worship. The same is true for ancient Egypt, India, or any of the pre muslim pre christian tribal religions. Odin never made war on the victims of Viking raids.
Religion and political power when intertwined make it more likely a religion is violent or has the potential for violence. Christianity is far less violent than the Roman Imperial religion, particularly the stuff for Mars In fact one of the criticism of Christianity is its tendency toward separation of church and state, and for peace bringing about the end of Rome and more promptly bring an end to the long Roman peace. Islam is not at all based on anything Roman but the hatred of Rome and that Rome and Constantinople were rivals, and where the gold, women, slaves were at.
Viking raids were very much in a religious tradition. The priests of the Hindu warrior caste are priests that lead the army, so the battles between Islam and Hindu were religious on both sides, with both sides independently weaving religion and political power together.
Judaism is violent just read the first five books in their entirety. When Christians met to determine the cannons of the religion one group argued for deep sixing the entire old testament because of freedom from the law, and the brutality and violence in the old testament.
Stalin was an opportunist and practical man. He was not an ideologue as Lenin was. So when the chips were down in WWII out came nationalism, appeals to mother Russia, and priests. When no longer useful they went to the gulag along with soldiers corrupted by Americans when they met in the Great War.