So says Ronald Reagan's epitaph, which you can view for yourself a few posts below this one.
Now, not just Christianity, but classical philosophy as well sees man as fallen. And as we look at the world around us, it's difficult to disagree with that. He used to be really great, not so much lately.
My buddy Aquinas would soften Reagan's formulation (as I did myself): that man is by nature (God-given nature?) capable, if not oriented, toward responding to good.
That should work theologically, as God, not man himself, is the source of all good, and if it is not true in reality, we're in for it, folks.
If Reagan didn't believe that people (in his case the captive nations of the Soviet empire) would embrace the freedom he helped precipitate, he would have gone about things differently, I think.
Bush, too. We're in the throes of deciding whether the Iraqi people really want peace, brotherhood, and all that blahblah. I still think they do, but we should not overestimate their courage (and, it appears lately, our own) or underestimate the chilling effect of a few very bad men.