“I have fought a good fight, I have finished my course, I have kept the faith:”
‭‭2 Timothy‬ ‭4‬:‭7‬

We don’t fight the world (with its lusts and pride, 1 John 2:16) of people or demons; Jesus said:
“…In the world ye shall have tribulation: but be of good cheer; I have overcome the world.” ‭‭John‬ ‭16‬:‭33‬
He already overcame! They are ineffective; see the lusts of the flesh in the world:
“And they that are Christ’s have crucified the flesh with the affections and lusts.” ‭‭Galatians‬ ‭5‬:‭24‬
See satan:
“…so that through [experiencing] death He might make powerless (ineffective, impotent) him who had the power of death—that is, the devil—” Hebrews‬ ‭2‬:‭14‬ ‭Amplified Bible
We fight the good fight of faith and that is simply remembering at every given moment that we are not victims but victors and as such we should not be overtaken by any challenge; instead of giving in, we remain standing! (Ephesians 6:14a) Only the word of God can give you such sturdiness in the face of opposition! If faith comes by hearing the word, then the fight of faith is the fight to remain in the word, and on the very real flip side- every opposition you face would be to get you out of the word through doubt, fear or unbelief.

Bible Reading Plan: Isahiah 24 and 1 chronicles 8