I don't think everyone agrees that deathbed conversions can wash away all sins, no matter how horrid. I will find out someday. As I said, Lee's maker may have forgiven him, I don't profess to know, as you do. Lee had good character on most of his life's conduct, but his poor judgment in the Civil War contributed to 500,000 deaths and sought to perpetuate slavery, which the Christian church declared wrong within decades of Jesus' death, in the writings of St. Paul. He certainly had something to seek forgiveness for.
Lee didn't own any slaves, he freed the slaves that were inherited from Mrs. Lee's side. He did what he thought was his duty. What would you do if an army was heading toward your home? Your hatred of Lee has skewed your sense of historical perspective.
Lee didn't start the war, he didn't want the war but felt bound by the sense of duty that was part of the chivalric code of the era.
You need to cite the verses Paul wrote condemning slavery. The verses I'm familiar with that he wrote told the masters to treat their slaves well and for the slaves to obey their masters.
Slavery of course is bad, but back in history many thought it was good because it introduced the slaves to Christianity. That's why it's difficult to judge those who lived in the past by today's standards.