I've been meaning to do this post for awhile, so I'll have something to link to for reference, because this point comes up a lot and it's already settled philosophy, and has been for hundreds of years -- even the theologians agree on this one! This will be old hat for almost anyone reading this, but I just want to get it down so I have something to link to.
Morality does not and CAN not come from God. The argument to show this is quite simple. Consider: What if God commanded you to eat babies? Would that make it moral? Three possible answers:
1) No it would not. Good for you. Hence, morality exists independent of God.
2) God would never command such a thing, because She is perfectly moral. Slightly trickier than the first, but this still proves that morality exists independent of God. The statement makes a prediction on what God would or would not say based on what is moral -- but if morality is defined by whatever God says it is, then this test is circular. The assertion becomes "God would never command such a thing, because He's never commanded such a thing." This is obviously unworkable. Therefore, in order to answer this way, one must posit a morality independent of God.
3) Yes it would. Well okay then. I would argue that anyone taking this position is fundamentally amoral, and I'd be rather frightened of them. Beyond that, many philosophers assert that morality cannot be synonymous with simple obedience, and that therefore this would not form a coherent morality either. I'm not sure if I think that part of the argument is bulletproof -- but I'm not worried about it, because as far as I'm concerned, as soon as somebody takes this position, I've won the debate.
Now, many people may still legitimately argue that God/belief in God helps them to be moral. I would almost always disagree, but this is a position that can be reasonably debated. It cannot be cleanly logically refuted; it must be debated on evidence. However, the position that morality does not exist without God is empty. It's dead. It's been defeated long long ago, and cannot be adequately defended.
Good, so now I can just link here instead of retyping this every time.