Micah 6 writes:
8 He hath showed thee, O man, what is good; and what doth Jehovah require of thee, but to do justly, and to love kindness, and to walk humbly with thy God.
A statement that can be interpreted in a whole spectrum of ways.
What is just? Each man will answer differently. Is it just to stone a man to death for picking up sticks on a certain day? Some men have answered yes. What does Jehovah require of me on this novel moral situation? What is kindness? Is it kindness to deliberately end the life of a terminally ill person who is suffering? Some have answered yes, some have answered no.
It is in these kinds of gaps that different versions of gods sharing the same name with the same holy books spring up
It is about having an unselfish worldview rather than a selfish one.
And the differing views of what constitutes selfishness and selflessness is another example of this. Some people might think that telling Africans that condoms cause AIDS is selfless because it saves them from angering God by using unnatural contraceptives. Others think it is dangerously putting forwards ones own beliefs at the tragic expense of other people, thus arguing that it is a very selfish act (and worse!).
Two Christians could easily find themselves at odds on these kinds of questions. Each of them has a concept of god and what it thinks is the kind, just, loving and humble course of action.
The examples of moral questions that you gave (robbing a person, failure to return lost wealth) are rather simple; when you get into the more difficult questions, that's where you see people's ideas for what a moral god would want begin to vary.
Unfortunately, these are all some of the most important moral questions we can typically have since they tend to involve life and death consequences.