You really should go back and read our founding fathers in their own words, because I think that you would be in for a real shock. They did endorse a religion, just not a branch of that religion gaining control of the daily lives of the people. They knew that when that religion began to wane that democracy would be finished.
Your comparison Islamic goverments(commanded in the koran) and any Christian here in the U.S. makes no sence and is disgusting. Where do you see Christians wanting that type of control(nobody is demmanding a Christian controled goverment with Christian laws)?? The comparison is right out of democrat talking points. Lets all demigog the Christians and make them as evil in public opinion as islamics, who cares for the facts. I guess you believe that Republicans are going to kill the elderly with their tax cuts, because it is the same line of thinking. If you say it enough the people will believe it is the truth.
If you are upset that Christians are worried about the moral degradation of society, maybe seeing it from the founding fathers point of view will help. They felt that with the decline of Christianity (self imposed morals) we would loose our democracy and freedoms. Look what is happening today, daily we loose a little more freedom, because we "need more laws" to deal with each new low in human behavior. We see homosexuality, a lowering of what is allowed on tv and games as fine, and see the rise of abduction of children, murder, rape, and of course need nation wide police computers to keep up. The more we lower the standards of behavior (self control) the more goverment will step in and take control of our lives all in the name of protection of the innocent and the need of freedom from government in our private lives.
This is where libertarians don't understand what they will get is anarchy and democrats a police state when they really get what they want. But, we will have freedom from morals.
I see "forgiveness" as a license for immoral behaviour amongst Christians.
W.J. Clinton, for example, is a poster-boy Christian.