On several occasions over the past few weeks I've read John Wesley's letter to William Wilberforce dated February 27, 1791 (Wesley died March 2nd). As Wesley prepared to pass from this life he sent some encouraging words to the famous abolitionist:
DEAR SIR, -- Unless the divine power has raised you up to be as Athanasius contra mundum, ['Athanasius against the world.'] I see not how you can go through your glorious enterprise in opposing that execrable villainy, which is the scandal of religion, of England, and of human nature. Unless God has raised you up for this very thing, you will be worn out by the opposition of men and devils. But if God be for you, who can be against you Are all of them together stronger than God O be not weary of well doing I Go on, in the name of God and in the power of His might, till even American slavery (the vilest that ever saw the sun) shall vanish away before it.
Reading this morning a tract wrote by a poor African, I was particularly struck by that circumstance, that a man who has a black skin, being wronged or outraged by a white man, can have no redress; it being a law in all our Colonies that the oath of a black against a white goes for nothing. What villainy is this!
That He who has guided you from youth up may continue to strengthen you in this and all things is the prayer of, dear sir,
Your affectionate servant. (Source)
For all those seeking to do good in the world, for those struggling for justice, especially those who share the Christian understanding of God with Wesley, these words remain an encouragement. Wesley compares Wilberforce to Athanasius who seemingly stood against the whole world as Arianism looked to win the hearts and minds of many Christians, even after the Council of Nicaea. Now, slavery, a shame for the religious, for the nation of England and for the United States, and against human nature was the great heresy that clouded the minds of people. Wilberforce seemed to stand alone, but he wasn't, and though Wilberforce's proposals did not pass on April 20th of that year—in fact, they didn't pass until sixteen years later in 1807—Wesley was right that neither the opposition of demons or humans was sufficient when someone was struggling for what is right because as hard as it may be to believe at times, God is with them, God is with us.
For more on this go to this website, scroll to footnote 18 which adds a lot of insight, some which I relayed in this post.