The fact that Gen. Lee trusted God more than men is all that is learned in the quote you cite. You will not be swayed by any history of Lees efforts to end slavery. You are only satisfied to play God as your heroes did and kill those that God himself never commanded to cease in this miserable institution. God taught that all men should be content and to honor Him in whatever their position was. He taught slaves to love and obey their masters. He taught slave holders to love and respect their slaves. And he worked on our hearts through His Word and Providence. He taught us how to change hearts. It was not by bullets and bombs, brothers against brothers.
The pen of one of Gen. Lee’s freed slaves will no doubt be denied by you. The Rev. William Mack Lee said this, “I was raised by one of the greatest men in the world. There was never one born of a woman greater than Gen. Robert E. Lee, according to my judgment. All of his servants were set free ten years before the war, but all remained on the plantation until after the surrender.” William Mack cooked for General Lee’s Confederate troops throughout the war. He stayed with him, because he loved and respected him.
Probably because Mack Lee was a fraud. Take a look at this quote from his book:
"The onliest time that Marse Robert ever scolded me," said William Mack Lee, "in de whole fo' years dat I followed him through the wah, was, down in de Wilderness--Seven Pines-- near Richmond. I remembah dat day jes lak it was yestiday. Hit was July the third, 1863."
"On dat day--July the third--we was all so hongry and I didn't have nuffin in ter cook, dat I was jes' plumb bumfuzzled. I didn't know what to do. Marse Robert, he had gone and invited a crowd of ginerals to eat wid him, an' I had ter git de vittles. Dar was Marse Stonewall Jackson, and Marse A. P. Hill, and Marse D. H. Hill, and Marse Wade Hampton, Gineral Longstreet, and Gineral Pickett and sum others."
On July 3rd, 1863 Lee was nowhere near Richmond. He was outside of Gettysburg getting ready to massacre Picket's men against the Union center.
Douglas Southall Freeman in his biography of Lee goes into detail on the members of Lee's headquarters. He mentions other servants of Lee. He doesn't mention Mack Lee.