To fight or not?

Οὔπω μέχρις αἵματος.… “Not yet unto blood have ye resisted in your contest with sin.” Bengel says: “a cursu venit ad pugilatum”. Cf. 1 Corinthians 9:24-27. But this is doubtful μέχρις αἵματος [Theoph., ἄχρι θανάτου, cf. Revelation 12:11.] Does this mean, Ye have not yet become a martyr church, suffering death in Christ’s cause; or does it mean, Ye have not yet resisted sin in deadly earnest? The interpretation is determined by the connection. Jesus endured the ἀντιλογία of sinners even to blood, the death of the cross; the Hebrews have not yet been called so to suffer in their conflict, a conflict which every day summons them to fresh resistance against the sin of failure of faith and apostasy. “ ‘Sin’ is not here put for sinners, nor is it sin in their persecutors; it is sin in themselves, the sin of unbelief, which is here regarded as their true antagonist, though of course the excesses of their persecutors gave it its power against them” (Davidson and Weiss).

Hebrews 12:4
You have not yet resisted to blood, striving against sin.