Hebrews 10:2

Ceased to be offered. That is, they would have ceased if they could have accomplished what the sacrifice of Christ did in perfecting forever (v. 14). Christ dealt with the sin problem once and for all. There was no need that His sacrifice be repeated (cf. ch. 9:25,26).

Once purged. Or, “once cleansed.” This cleansing did not take place until Christ “offered himself” (ch. 9:14). Only then was there remission for the transgressions that were under the first covenant (ch. 9:15).

No more conscience. Or, “no more consciousness” (cf. on ch. 9:9). At best the OT worshiper could, by faith, look forward to the time when the real sacrifice for sin should be made. If faith was lacking, his worship was dead and formal indeed.