1, exactly, is not exactly the same, and it has nothing to do with spoken English, because both are spoken English. The difference is that my God, who mainly believes in Christianity or Catholicism in the west, is first used by these theists, while my God is used by atheists.
2. Now, my god is used to do serious things, and my god can be used to do any small things like onion, ginger and garlic.
3. For Christians, calling my God to express surprise is disrespectful to God and a rude and uncivilized expression, so there are euphemistic expressions such as My God, My God and so on. The meaning has not changed.
4. For Christians, calling my God to express amazement is disrespectful to God and a rude and uncivilized expression, so euphemistic expressions such as My God, My God and so on. It has already appeared, but the meaning has not changed.