I think of David Livingstone, the pioneer missionary to Africa, who walked over 29,000 miles. His wife died early in their ministry and he faced stiff opposition from his Scottish brethren. He ministered half blind. His kind of perseverance spurs me on. As I run, I remember the words in his diary: Send me anywhere, only go with me. Lay any burden on me, only sustain me. Sever me from any tie but the tie that binds me to Your service and to Your heart.