The story
A translation of the Koine Greek phrase ἀγωνίζου τὸν καλὸν ἀγῶνα τῆς πίστεως (agōnízou tòn kalòn agôna tês písteōs, “fight the good fight of faith”) in 1 Timothy 6:12 that appeared first in the Tyndale Bible, then in the King James Version.
Etymology from Wiktionary, CC BY-SA 4.0.