1 Corinthians 9:25-27 New English Translation (NET)

25. Each competitor must exercise self-control in everything. They do it to receive a perishable crown, but we an imperishable one.

26. So I do not run uncertainly or box like one who hits only air.

27. Instead I subdue my body and make it my slave, so that after preaching to others I myself will not be disqualified.

1 Corinthians 9