The ethical good of an end, or goal, is not of itself sufficient to justify any unethical acts which are designed to produce the end. Intelligent men have debated this. Is it ethical to kill one man to save the lives of many? Is it ethical to rob from a rich man to give the goods to a poor man, or to rob from a poor man to give to a rich man? To steal from a thief to return it to the original owner? The ethics are not always clear, and rabbis have made plenty of commentary text on the margins.
I think it means that what you see maybe actually not what is real or what you have now does not show or tell how you got it. You may be wealthy now, but that does not mean you should have pride. For all we know, you could have stolen the money.