Here’s the correct reasoning:
If God X exists, there are God X’s moral values, not objective moral values, and because there is more than one faith, humans will have different moral values. If no Gods exist, humans will have different moral values. Therefore, there are no objective moral values.
So Harris is wrong, and Craig makes his usual effort.
Morals is why we have politics and legislation, and we can hope that agreement comes for moral rules that are the most beneficial for all or most of us, as we make the people more informed to make the right choices as times change.
But anything beyond that is enforced consent.