Wesley's self-assessment

Friday, June 28.--I am seventy-three years old and far abler to preach than I was at three-and-twenty. What natural means has God used to produce so wonderful an effect? 1) Continual exercise and change of air, by traveling above four thousand miles in a year; 2) constant rising at four; 3) the ability, if ever I want, to sleep immediately; 4) the never losing a night's sleep in my life; 5) two violent fevers and two deep consumptions. These, it is true, were rough medicines: but they were of admirable service, causing my flesh to come again as the flesh of a little child. May I add, lastly, evenness of temper? I feel and grieve, but, by the grace of God, I fret at nothing. But still "the help that is done upon earth, He doeth it Himself." And this He doeth in answer to many prayers. 

The Journal of John Wesley