Help me out here

[Theophylact]

What does Bush mean by this?

By a plan known only to Providence, the stolen sons and daughters of Africa helped to awaken the conscience of America. The very people traded into slavery helped to set America free.

If we hadn't had slavery, we'd have been the poorer for it, because slaves awakened our conscience to the evils of slavery?

It's not only the ways of God that are mysterious...

Convoluted Bush-speak. Don't think even he understood what he said.