OK, let's take the next sentences as well:
"While we see the course of the final abolition of human slavery is still onward, and give it the aid of our prayers, let us leave the progress as well as the results in the hands of Him who, chooses to work by slow influences, and with whom a thousand years are but as a single day. Although the abolitionist must know this, must know that he has neither the right not the power of operating, except by moral means; that to benefit the slave he must not excite angry feelings in the master; that, although he may not approve the mode by which Providence accomplishes its purpose, the results will be the same; and that the reason he gives for interference in matters he has no concern with, holds good for every kind of interference with our neighbor, -still, I fear he will persevere in his evil course..."
Lee was willing to leave slavery in the hands of God. He viewed any attempts to end it my abolitionists as an "evil course." He did, as I mentioned earlier, consider it "necessary" for blacks if they were to advance as a race, and a much better condition for them than as free men in Africa. And you still say he was opposed to slavery?
Your arguments are pretty much the same as the Supreme Court deciding on issues out of their jurisdiction (e.g. the definition of marriage). Lee is correct, there are things that must be left in the hands of God doing his work on men’s souls. The abolitionist wants to play god.