When Christ came as high priest of the good things that are already here, he went through the greater and more perfect tabernacle that is not man-made, that is to say, not a part of this creation. 12 He did not enter by means of the blood of goats and calves; but he entered the Most Holy Place once for all by his own blood, having obtained eternal redemption.

(Heb. 9:25-28) Nor did he enter heaven to offer himself again and again, the way the high priest enters the Most Holy Place every year with blood that is not his own. 26 Then Christ would have had to suffer many times since the creation of the world. But now he has appeared once for all at the end of the ages to do away with sin by the sacrifice of himself. 27 Just as man is destined to die once, and after that to face judgment, 28 so Christ was sacrificed once to take away the sins of many people; and he will appear a second time, not to bear sin, but to bring salvation to those who are waiting for him.

The point is emphasized that the Mosaic covenant is inferior because it provided only a temporary salvation. After the priest performed his sacrificial ritual, the sinner was forgiven — but only until he sinned again. The forgiveness was brief and temporary. However, the forgiveness we receive from Jesus is continuous and unending. We are made perfect forever.

(Heb. 10:1-4) The law is only a shadow of the good things that are coming — not the realities themselves. For this reason it can never, by the same sacrifices repeated endlessly year after year, make perfect those who draw near to worship. 2 If it could, would they not have stopped being offered? For the worshipers would have been cleansed once for all, and would no longer have felt guilty for their sins. 3 But those sacrifices are an annual reminder of sins, 4 because it is impossible for the blood of bulls and goats to take away sins.

The author is setting up a further contrast. The Mosaic covenant does not really make the worshipers perfect in God’s eyes. Nor does it cleanse them once for all. But the new covenant does make us perfect forever and cleanse us once for all.

This is in direct contrast to the conservative theory. Christian forgiveness is “once for all” and does not require endless repetition. We don’t repent, get forgiven, get damned, repent, get forgiven — on and on. Rather, God “cleansed once for all” and made us “perfect forever”!