Stephen Covey, in his Seven Habits of Highly Effective People, summed it up well. To determine whether or not a principle is correct, just visualise what the world would be like if everybody didn't practice it.
Having a religious leader lay down the law about what is right and what is wrong only works to the extent that religious people apply those principles. And there's the rub! All too many religious people (with Christians noteworthy among them) fail to practice what they preach.
This did not go unnoticed amongst the "heathen" peoples of Africa, Asia and elsewhere. For example, in 19th Century New Zealand, the newly-converted Maori people were quick to observe how the Ten Commandments were relegated to second place from Monday morning until midnight Saturday - then sent on an indefinite Leave of Absence whenever there was a war on!