Charles Spurgeon Commentary 2 Timothy 2:5

"And if also a man contend in the games, he is not crowded, except he have contended lawfully." — 2 Timothy 2:5 (ASV)

And if a man also strive for masteries, yet is he not crowned, except he strive lawfully. (2 Timothy 2:5)

There were rules in the Grecian games. When they struck each other, the blow was not to be given except upon a certain part of the body, and if a man fought unlawfully, he could not get the prize. So there are laws, too, for the Christian ministry, and also holy regulations for the great wrestling of Christians.