Quite right. God is the ultimate authority for right and wrong. Otherwise, laws are simply arbitrary enforceable by those with the most power for their own personal desires.
A good example is murder- why is it wrong? Either God says its wrong or it really doesn't matter who kills who and why.
Example: If you were to say murder was wrong (and left God out of the picture), what ultimate authority could you point to say that I or anywone couldn't kill you simply because we felt like it?
Ultimately then, moral absolutes descend from God or all you have is anarchy as your absolute.
What about the morals of those who don't share your belief in "God" what do you think makes them not do those things?