Most Bible translations say something like he will ‘fight the good fight.’ However, in our opinion, Paul wanted to use a much stronger imagery.
The Greek source seems to indicate that Timothy would act as soldier or warrior in fighting (strateun) in a good (kalen) war (strateian). Presumably, this would be a spiritual war.
What may be the original Aramaic source agrees, saying that Timothy would perform military work or service (dəṯeplūḥ) in a good, or proper, (šappīrtā) war (pālḥūṯā).
We feel that this is more colorful than merely ‘fight a good fight’. It is also logical, because both letters to Timothy follow a theme of a soldier in battle. For example, Paul refers to him as a ‘fine soldier’ at 2 Timothy 2:3-4.