I will have to admit I was wrong (I do that when I'm wrong - do you?) and grant you that some Christians did support slavery and some refused to fight for its eradication, however, some of these men may have had a blind spot. I do believe slavery was wrong. However, nowhere in the bible does it explicitly command people to FREE SLAVES, rather it says to LOVE THEM, because if you love a person, you will want to do right by them. Love covers a multitude of sins. Washington freed his. Undoubtedly, I agree that some Christians owned slaves, but I would contend that this was a blind spot for them, as some believed that it was God's will - perhaps the African nations were under judgment. Only God knows, however.
As men, our founders were flawed, not perfect, but they had more morality in their little finger than the moral relativists of today, who have no morals whatsoever other than those dictated by themselves or their ideology.
The Northwest Ordinance speaks for itself. So does the fact that it was Christians (first in England with Wilberforce, then in the U.S.) who took the lead in eradicating slavery. Simple facts.
It's certainly true that the anti-slavery movement was led by Christians (or at least post-Enlightenment non-Christians.) Jefferson didn't free his slaves (I think primarily because he couldn't afford the fees or some similar problem) but Washington did and (I think) Lee did.
Had there been statesmen of enough vision in the 1820-1860 time frame, the slaves could have been freed and the Civil War (and Reconstruction and devastation of the South rivaling that of the Mongols in the Middle East) possibly could have been avoided.