In our Bible study at church we are working our way through Hebrews and in my own daily reading I have been in Ezekiel. Recently I have read through the last 8 chapters concerning the millennial temple.  It's been very interesting to me to compare some of the statements made in Hebrews with what we read in the last 8 chapters of Ezekiel.  I have to say that I have questions without answers.

Here, we have offerings re-instituted. I've had this on my mind for some time now because the difference in the content of the two books is quite striking. Hebrews is all about one offering forever and here in the millennial temple we find further offerings. I was wondering what your thoughts are on this as I'm struggling with it.

You certainly are not the only one wondering about these sacrifices. I just came across a summary of an article by Charles C. Ryrie from "Emmaus Journal 11" (winter 2002) called "Why Sacrifices in the Millennium?" It deals with the same problem of explaining the purpose of sacrifices in Ezekiel 40-46 where the text clearly refers to the millennial temple.  Ryrie gives three reasons (which I will put in my own words).

1. To provide temporal forgiveness for the sins of those living in the kingdom. The keeping of the law in the Old Testament never gave eternal life, so it certainly will not do so in the kingdom. However, they will need to keep a working relationship with God--much as we do when we ask for forgiveness of sins for the purpose of a right daily walk. We already have all our sins forgiven as to our eternal home, but we need to keep things right between us and God for our daily walk. The sacrifices may even be used to keep the wrath of God at bay for those who are not saved.  It could simply be a way of avoiding God's anger against sin. See Zechariah 14:16-19 [16] And it shall come to pass, that every one that is left of all the nations which came against Jerusalem shall even go up from year to year to worship the King, the LORD of hosts, and to keep the feast of tabernacles. [17] And it shall be, that whoso will not come up of all the families of the earth unto Jerusalem to worship the King, the LORD of hosts, even upon them shall be no rain. [18] And if the family of Egypt go not up, and come not, that have no rain; there shall be the plague, wherewith the LORD will smite the heathen that come not up to keep the feast of tabernacles. [19] This shall be the punishment of Egypt, and the punishment of all nations that come not up to keep the feast of tabernacles.
   See All... and consider how God stops the rain to those nations who refuse to come up to Jerusalem at the feast of tabernacles. This is also kingdom age doctrine.
2. To point to the Saviour. Just as the OT sacrifices pointed to Christ in type, so the sacrifices can be a living reminder of the ways in which Christ fulfilled the sacrifices. They will show that the reigning Sovereign is also the suffering Saviour. When we keep the Lord's Supper, we do it in remembrance of Christ (1 Corinthians 11:24-25 [24] And when he had given thanks, he brake it, and said, Take, eat: this is my body, which is broken for you: this do in remembrance of me. [25] After the same manner also he took the cup, when he had supped, saying, This cup is the new testament in my blood: this do ye, as oft as ye drink it, in remembrance of me.
   See All...). Christ has already died, yet we memorialize His death on the cross when we take of the bread and fruit of the vine. This would be perfectly proper for the kingdom age. They would provide the Old Testament pictures without the veil hiding their meaning (2 Corinthians 3:13-15 [13] And not as Moses, which put a vail over his face, that the children of Israel could not stedfastly look to the end of that which is abolished: [14] But their minds were blinded: for until this day remaineth the same vail untaken away in the reading of the old testament; which vail is done away in Christ. [15] But even unto this day, when Moses is read, the vail is upon their heart.
   See All...).
3. To provide an opportunity for obedience to the kingdom saints in order to bear fruit and give evidence of their faith.

Though I do not have an exact statement of purpose in scripture, these reasons make a lot of sense to me. However, there is one beautiful picture that I want to tell you about. In the kingdom age, when the people of the land come to worship in the temple complex in the solemn feasts, they may enter either by the north gate or by the south gate (Ezekiel 46:9But when the people of the land shall come before the LORD in the solemn feasts, he that entereth in by the way of the north gate to worship shall go out by the way of the south gate; and he that entereth by the way of the south gate shall go forth by the way of the north gate: he shall not return by the way of the gate whereby he came in, but shall go forth over against it.
See All...). However, when they leave after meeting with "the prince in the midst of them" (v.10), they are to leave by the gate opposite the one they entered. In other words, if they entered the north gate, they are to leave by the south gate. And, if they entered by the south gate, they are to leave by the north gate. The man who worships there "shall not return by the way of the gate whereby he came in" (v.9).

This is a wonderful picture of the effect that the kingdom sacrifices are to have on the people who participate in them. They are not to leave in the same way they entered. In type, they should be changed by what they have seen. It is also a great picture of how we should enter and leave church services today.

In conclusion, though I do not have a perfect answer to your questions, I do not see any serious problem with God requiring sacrifices of the earthly saints during the kingdom age.