First of all, we are told that we have been sanctified by means of Christ’s sacrifice “once for all” (Hebrews 10:10). That entails His work being fully complete at Calvary. His sacrifice is not continuing on in worship services across the world because that historical event has already come to pass. There is no sense in which His work is still in progress.
Priests repeatedly offer the same sacrifices in vain as a result of Christ’s expiatory work on the cross (Hebrews 10:11). They are powerless to accomplish anything for a person’s benefit. Why would we need an ordained ministerial priesthood to offer up Jesus Christ as a sacrifice when He has already given Himself up as a ransom for sin and so rendered ritual sacrifices to be of no avail? This point is articulated more explicitly in verse 18.
Jesus Christ has ascended into the full presence of God (Hebrews 10:12). He is, in the present tense, waiting to subdue His enemies at the perfect timing (Hebrews 10:13). Thus, He is not coming down from heaven at the command of a parish priest. Nor can His physical body be located in thousands of different Roman Catholic congregations at the same time.