Ye have not yet resisted unto blood, striving against sin.
Not yet resisted unto blood - image from pugilism, as from a race; both taken from the national Greek games. Ye have suffered the loss of goods, and been a gazing-stock both by reproaches and afflictions (Hebrews 10:33-34: ye have not shed your blood, note, Hebrews 13:7). 'The athlete who hath seen his own blood, and though cast down by his opponent, does not let his spirits be cast down, who, as often as he falls, rises the more determined, goes to the encounter with great hope' (Seneca).
Against sin - personified as an adversary; whether within, leading you to spare your blood, or in your adversaries, leading them to shed it, if they cannot, through your faithfulness, induce you to apostatize.