It was Hitler's root philosophy to spread influence to the Germans about the glory of the superior Aryan race and he came at the right time when the German Empire was crumbled after the First World War and he wanted to bring back to its former glory and he did that (where he was actually democratically elected) by scapegoating the Jews by the wrongs of the world.
But why exactly? Why did Hitler hate Jews so much that he actually wanted to kill millions of them (and even target other minorities that are not Aryan like the Gemani, the Gypsies and so on)?
I heard that the Jews as scapegoats during that time in history similar to how the U.S. culture used to target the Muslims as terrorists for the evils of the world during the beginning of the 21th Century but I am not sure if that had an effect in Hitler's motivation of antisemitism.
EDIT ... Did other countries of the world actually believed and supported Hitler's antisemitism ideology as well?
Hi there, you may be interested in a couple of these older answers from u/commiespaceinvader:
and
https://www.reddit.com/r/AskHistorians/comments/4cewq8/on_adolf_hitler_great_man_theory_and_asking/
The first one answers your question directly, while the second one, while not meant to discourage you from asking questions, does offer a way to think about Hitler as being not particularly interesting or important:
The private thoughts of Adolf Hitler do not hold the key for understanding Nazism and the Holocaust. Adolf Hitler, like any of us, is in his political convictions, in his role of the "Führer", in his programmatics, and in his success, a creation of his time. He is shaped by the social, political, economic, and discursive factors and forces of his time and any attempt at explaining Nazism, its ideology, its success in inter-war Germany, and its genocide will need to take this account rather than any factors intrinsic to the person of Adolf Hitler. Otherwise we end up with an interpretation along the lines of the great man theory of the 19th century which has been left behind for good reason.