But this man, after he had offered one sacrifice for sins for ever, sat down on the right hand of God; (Hebrews 10:12)
Jesus ended the sacrifices and ended the Law!
A closer examination of the Hebrews verse used reveals the error of this objection:
Hebrews doesn't say that Christ was the final sacrifice. It says he offered one sacrifice for sins for all time. Hebrews is saying that Jesus' sacrifice is the one and only sacrifice required to pay for our sins.
The blood of bulls and goats can never take away sins... it's impossible! (Hebrews 10:4) They must have had some other purpose and Christ's sacrifice for sin was unrelated.
There are all kinds of sacrifices [Hebrew: qorbanot] that have nothing to do with sin. For example, there is the burnt offering, the meal/bread offering, and the peace offering. The wave offering, the heave offering, the fire offering, the drink offering, and the offering made by the cleansed leper (unless you consider leprosy itself to be related to sin). Hebrews says nothing about these ending.
Ezekiel speaks of the time when Messiah returns and describes all kinds of sacrifices that will occur. Zechariah tells us that in the time of Messiah, if a nation does not come up to celebrate Sukkot (with all its attendant sacrifices and offerings) they will have no rain.
There will still be sacrifices (unrelated to the removal of sin, of course) when Messiah reigns. You can learn more about this in our article about the Sacrifices.