"St Nick (Santa) was a real person. And he didn't threaten to burn alive the children who didn't believe he was real." Tina Outwest
Neither does God. You are creating a straw man that you take great joy in easily tearing down. The justice of God will see to it that Hitler gets what is due to him, but He warns that He will punish all evil.
Some ask the question, "If God is good, how can Hell exist?" In the face of all the evil in the world, the real question is, "If God is good how can Hell NOT exist?" There will be a Day of absolute and eternal Justice. That is frightening for God-hating, blasphemous rebellious sinners. Think you are safe and don't need His mercy? The try this little test: www.needGod.com