1 Corinthians 9:25
And every man that striveth for the mastery is temperate in all things. Now they [do it] to obtain a corruptible crown; but we an incorruptible.
Note 13 at 1Co 9:25: "Striveth" was translated from the Greek word "AGONIZOMAI," and this Greek word means "to struggle, literally (to compete for a prize), figuratively (to contend with an adversary), or genitive case (to endeavor to accomplish something)" (Strong's Concordance). Our English words "agonize" and "agony" come from the same root word as AGONIZOMAI.