George Foreman was a two-time heavyweight boxing champion of the world. At age 45, he became the oldest man in the world to win the title. In his book, God in My Corner, he writes
When I started my comeback, I had to get rid of some excess George. I was extremely overweight. In the nearly ten years I had been out of boxing, I had ballooned from 220 to 315 pounds. And it wasn’t muscle that I gained!
To get back into an exercise regimen, I started with the basics—running every day. I was so out of shape that I couldn’t go far. At first, I couldn’t even make it around my block, which was about a mile. I had to stop a few times to catch my breath, huffing and puffing.
Just imagine a big, fat guy, gasping for air, barely able to jog around the block, who claims that he will be the heavyweight champion of the world again! I looked ridiculous to everyone who saw me. I’m sure they laughed as they peeked through their curtains early in the morning while I slowly shuffled past their houses. Only two people on this entire planet believed I could recapture the title—my wife and me.
But I had to get my weight down. I would walk and run, walk and run. Finally, I was able to run the whole time without walking. Then I began running longer distances, and with the combination of a proper diet and regular exercise, the fat continued to melt away. I kept running for the next eight months, until I finally got down to my fighting weight—229 pounds. The flab was fun to put on, but hard to take off. However, I wouldn’t have won the championship title if I first hadn’t gotten rid of that extra weight.
(George Foreman, God In My Corner, Nashville: Thomas Nelson, 2007, p. 169)
In similar fashion, our habits of sin can become dead weight that prevents us from effectively engaging in spiritual warfare. Spiritual discipline is absolutely essential.
I do not fight like a man beating the air. No, I beat my body and make it my slave.