Good and Evil are, of course, real. Just like the space shuttle, they are human constructions.
Interestingly all but a few of peoples throughout recorded history agree on what constitutes "good" (mercy, courage, love,honesty, justice, integrity) and "evil" (hypocrisy, sadism, hatred, dishonesty).
The fact that individuals so often fail to put this knowledge into practise is another issue. All religions have a version of the "golden rule", which is considered good. True, like so many words, "good" and "bad" are hard to define, but everybody understands what someone --even from another culture-- means when they use them, even if they don't believe that they are being applied correctly.
Anyone who tries to argue that there is no "good" or "evil" is, in my opinion, like the person who tries to argue that there is no objective reality: it's a cute exercise for teenagers exploring philosophy for the first time while sharing a joint, but that's about it.
If we didn't agree on the reality of these words, we'd have no reason to criticise Bush or Stalin
.