On December 4, 1857, David Livingstone, the great pioneer missionary to Africa, made a stirring appeal to the students of Cambridge University, showing that he had learned through years of experience what Jesus tried to teach Peter:
For my own part, I have never ceased to rejoice that God has appointed me to such an office. People talk of the sacrifice I have made in spending so much of my life in Africa. Can that be called a sacrifice which is simply paid back as a small part of a great debt owing to our God, which we can never repay? Is that a sacrifice which brings its own blest reward in healthful activity, the consciousness of doing good, peace of mind, and a bright hope of a glorious destiny hereafter? Away with the word in such a view, and with such a thought! It is emphatically no sacrifice. Say rather it is a privilege. Anxiety, sickness, suffering, or danger, now and then, with a foregoing of the common conveniences and charities of this life, may make us pause, and cause the spirit to waver, and the soul to sink; but let this only be for a moment. All these are nothing when compared with the glory which shall be revealed in and for us. I never made a sacrific
John Piper, Desiring God (Sisters, Or.: Multnomah Publishers, 2003), 243.