23 Now there have been many of those priests, since death prevented them from continuing in office; 24 but because Jesus lives forever, he has a permanent priesthood. 25 Therefore he is able to save completely those who come to God through him, because he always lives to intercede for them.
26 Such a high priest truly meets our need—one who is holy, blameless, pure, set apart from sinners, exalted above the heavens. 27 Unlike the other high priests, he does not need to offer sacrifices day after day, first for his own sins, and then for the sins of the people. He sacrificed for their sins once for all when he offered himself.
Working back to the old Jewish system of sacrifices, Jesus throws a stopper; He's both the priest and the sacrifice to end them all. We sometimes take that for granted; the Catholics seem to have a better handle on that, for they lean towards a crucifix with Jesus still on the cross rather than a empty cross.
The case for a blank cross is that Jesus moved on and rose again, but Jesus did die not just for the sins of this generation, but the ones to come. In that way, His death is an ongoing saving reality as well as His eternal life. I'm not quite to a point of saying He is dying for our sins rather than He died for our sins, but the cross doesn't lose its freshness two millennia in.