The gospel means freedom. The gospel means equality. The gospel means grace. The gospel means mercy. Wilberforce understood that Christ died for all, both free and slave and that all are made in the image of God and therefore worthy of justice. It was the gospel message of Christ that drove him to defend the defenseless, love the loveless, and fight for the helpless.
What Wilberforce leaves behind is not just justice for those who were denied it, or the imperative and possibility of being a Christian and yet a politician, but that the power of the gospel knows no ends. Wilberforce had a mountain to climb and through power of the cross, God used him to bring down a horrendous institutions in Western history.
Let Wilberforce be a reminder to Christians today that God moves mountains through the power of the cross. But the gospel is not just a social message, it is a spiritual message with social implications. Christ died in my place. Now, let us go living as He died.
I strongly encourage you to watch this video which surveys his life and legacy. Here is the trailer for the movie "Amazing Grace" which is based on his life
Also, watch the movie "Amazing Grace"