Thomas Boston, Human Nature in Its Fourfold State:
God the Father takes the pen, dips it in the blood of his Son, crosses off the sinner’s accounts, and blots them out of his debt-book.
The sinner outside of Christ is bound over to the wrath of God; he is under an obligation in law to go to the prison of hell, and there to lie until he has paid the utmost farthing. But now, being united to Christ, God says, ‘Deliver him from going down to the pit; I have found a ransom!’ (Job 33:24). The sentence of condemnation is reversed, the believer is absolved, and set beyond the reach of the condemning law. His sins, which were set before the Lord (Psalm 90:8), so that they could not be hidden—God now takes and casts them all behind his back (Isaiah 38:17).
Yes, he casts them into the depths of the sea (Micah 7:19). What falls into a brook may be retrieved—but what is cast into the sea cannot be recovered. But there are some shallow places in the sea; true—but their sins are not cast in there—but into the depths of the sea; and the depths of the sea are devouring depths, from whence they shall never come forth again. But what if they do not sink? He will cast them in with force, so that they shall go to the bottom, and sink as lead in the mighty waters of the Redeemer’s blood.