Hebrews 10 Forget About It!

11Day after day every priest stands to minister and to offer again and again the same sacrifices, which can never take away sins. 12But when this Priest had offered for all time one sacrifice for sins, He sat down at the right hand of God. 13Since that time, He waits for His enemies to be made a footstool for His feet, 14because by a single offering He has made perfect for all time those who are sanctified.
15The Holy Spirit also testifies to us about this. First He says:
16“This is the covenant I will make with them
after those days, says the Lord.
I will put My Laws in their hearts
and inscribe them on their minds.”b
17Then he adds:
“Their sins and lawless acts
I will remember no more.”c
18And where these have been forgiven, an offering for sin is no longer needed.

This Priest, notice it is not priest but Priest referring to Jesus Christ Himself!

Let's read this verse again; "12But when this Priest had offered for all time one sacrifice for sins, He sat down at the right hand of God."
ii. Spurgeon pointed out that the comma can be placed differently in the sentence, after He had offered one sacrifice for sins forever, sat down at the right hand of God. It is possible to translate, after He had offered one sacrifice for sins, forever sat down at the right hand of God. Either one is permitted and either one is correct, though the common translation is probably preferred. (Guzik)

"He has made perfect for all time those who are sanctified."
Sanctified
i. “What a glorious word! Those for whom Christ has died were perfected by his death. It does not mean that he made them perfect in characters so that they are no longer sinners, but that he made those for whom he died perfectly free from the guilt of sin. When Christ took their sins upon himself, sin remained no longer upon them, for it could not be in two places at one and the same time.” (Spurgeon)

c. The Holy Spirit also witnesses to us . . . says the Lord: In this passage, the writer to the Hebrews clearly shows that the Holy Spirit is the Lord, Yahweh of the Old Testament. When the Holy Spirit speaks, the Lord speaks. (Guzik)
Let this sink in!

Inner transformation; "I will put My Laws in their hearts and inscribe them on their minds.”"

Forgot about it!
iii. Their sins and their lawless deeds I will remember no more: The new covenant offers complete forgiveness. The forgiveness is so complete that God can say that He doesn’t even remember our sins in light of the new covenant!
iv. The Christian must endeavor to do with their sin exactly what God has done: forget about it. As well, this reminds us that the believer is in no way on probation. Before God, past sin has no bearing on God’s present dealing. (Guzik)

ii. “The Christ who died on Calvary’s cross, will not have to die again for my new sins, or to offer a fresh atonement for any transgressions that I may yet commit. No; but, once for all, gathering up the whole mass of his people’s sins into one colossal burden, he took it upon his shoulders, and flung the whole of it into the sepulcher wherein once he slept, and there it is buried, never to be raised again to bear witness against the redeemed any more for ever.” (Spurgeon)

God is working in us (you) for inner transformation (heart change). Our sins and lawless deeds are remembered no more, forget about it (them).
Spurgeon says it best, "and there it is buried, never to be raised again to bear witness against the redeemed any more for ever.”"

Blessings, David