In the New Testament we read that “it is impossible for the blood of bulls and goats to take away sins” (Heb 10:4) and that “we have been sanctified through the offering of the body of Jesus Christ once for all” (Heb 10:10). And yet Ezekiel 40-48 seems to speak of a future temple in which sacrifices will be made, including sin offerings (Ezek 40:39, 42:13, 43:19-25, 44:27-29, 45:17-25, 46:20). These two ideas seem inconsistent. If Christ has offered himself once for all, there should be no further need for temples or sacrifices. “Where there is forgiveness of these, there is no longer any offering for sin” (Heb 10:18).
One suggestion for reconciling these two ideas is that the future temple would be for the mortal population, rather than those who believed in Christ and have been raised immortal. For these people the new temple would serve as a learning experience, just as the old temple was a learning experience for the Israelites. The old temple is described as being symbolic of the true realities (see Heb 9:1-10). The sin offerings did not take away the sins of the people but were a reminder of sin (Heb 10:3). So, it is suggested, in the future temple there will be sacrifices to teach people about sin, until such time as they are ready to accept the truth in Christ.
This is being said, not everyone thinks that Ezekiel 40-48 predicts that there will be a future temple in the Kingdom age. One alternative view is that the temple described is actually symbolic of something else – it is not referring to a literal temple but is referring to something else in a symbolic way. However, it is not immediately clear what the symbols are intended to refer to. Another view is that Ezekiel 40-48 describes what the temple should have been like after the return from exile and that this prophecy went unfulfilled. Those who rebuilt the temple at the time of Haggai and Zechariah simply failed to live up to the intentions for the reconstructed temple that Ezekiel describes. If this is the case then we should not expect there to be a physical temple (with sacrifices) in the Kingdom age.