I listened to a great talk by John Piper the other day. It was an inspiration. He spoke on William Wilberforce (you can find it here: http://www.desiringgod.org/ResourceLibrary/Biographies/1492_Peculiar_Doctrines_Public_Morals_and_the_Political_Welfare)
What an amazing man Wilberforce was. He was driven by his love of Jesus to his life work of ridding my country of the slave trade. (The grand object of my parliamentary existence [is the abolition of the slave trade]. . . Before this great cause all others dwindle in my eyes, and I must say that the certainty that I am right here, adds greatly to the complacency with which I exert myself in asserting it. If it please God to honor me so far, may I be the instrument of stopping such a course of wickedness and cruelty as never before disgraced a Christian country.) He never seemed to become despondent by the many times the Bill failed; in fact, it seemed to strengthened him. His life was full of human disappointment: Ill-health, a wife who perhaps didn't have his passion for life, wayward children, constant personal attack, etc etc. This man rested on God and worked for Him.
This quote is just great: My grand objection to the religious system still held by many who declare themselves orthodox Churchmen. . . is, that it tends to render Christianity so much a system of prohibitions rather than of privilege and hopes, and thus the injunction to rejoice, so strongly enforced in the New Testament, is practically neglected, and Religion is made to wear a forbidding and gloomy air and not one of peace and hope and joy.
As Christians we fail so much when we forget the joy of the Lord in our daily walk. If all Christians were as focussed on God as Wilberforce was, it would be phenomenal to see what we could achieve in the 21st Century.