Would you please explain?
The context has to do with the one time sacrifice of Jesus through which he perfected for all time those who are being sanctified, over against the Old Covenant sacrifies that weren't able to perfect anyone because they were offered over and over. Notice the writer says:
And let us consider how to stir up one another to love and good works, not neglecting to meet together, as is the habit of some, but encouraging one another, and all the more as you see the Day drawing near. (Hebrews 10:24-25 ESV)
Right after that, he says:
For if we go on sinning deliberately after receiving the knowledge of the truth, there no longer remains a sacrifice for sins, but a fearful expectation of judgment, and a fury of fire that will consume the adversaries. Anyone who has set aside the law of Moses dies without mercy on the evidence of two or three witnesses. How much worse punishment, do you think, will be deserved by the one who has trampled underfoot the Son of God, and has profaned the blood of the covenant by which he was sanctified, and has outraged the Spirit of grace? For we know him who said, “Vengeance is mine; I will repay.” And again, “The Lord will judge his people.” It is a fearful thing to fall into the hands of the living God. (Hebrews 10:26-31 ESV)
This is talking about folks who heard the truth and turned away. You're trying to use this to talk about Christians who continue struggling with sin. That's not at all what the writer was talking about. We're talking about true Christians and indwelling sin. The writer of Hebrews was talking about people who had a profession of faith and then turned their back on it.