"doing unto others as we would have others do to us"
Do some research. The Golden Rule is found in every single philosophy and religion people adhere to. And Christians are no more successful at compliance rates than any other group of people.
Charity is also found in every religion and philosophy.
Slavery was abolished in many European countries before we abolished it.
It took a brutally-fought civil war roughly 90 years after the Declaration of Independence's principle that all men were created equal to abolish slavery. It took a civil rights movement roughly 190 years after that stated principle to bring "all men are created equal" to reality.
And Christians were on both sides of both struggles.
All these years later, some women are still wondering whether the principle applies to them.
And where do charity or the Golden Rule show up in the founding of this country?
So, you're batting .000 on exclusively Christian principles founding this country.