Thanks Hakawaka, for you question about whether animal sacrifices would be reinstituted during the millenium.
First of all, in my opinion, the millenium is not an occurance in the sense that some groups of men claim. We read about the scripture pertaining to this idea of the millenium here:
"Blessed and holy is he that hath part in the first resurrection: on such the second death hath no power, but they shall be priests of God and of Christ, and shall reign with him a thousand years. "
This is talking about all who are true believers in Christ. When someone believes the gospel they become blessed and they become holy. That's the what the verse says. They have part in the first resurrection, meaning they have part in Christ's resurrection from the cross and subsequent grave. He was the first to be resurrected from the grave. That was the first resurrection. The born again believer is able to be given spiritual new life in Christ because Jesus was the first to resurrect and to send the Holy Spirit. The believer has a part in this, because the Holy Spirit was able to be sent due to this resurrection. The second death has no power over them, meaning that they will not perish with unbelievers. Their first death was when they were a part of the fallen human race and could expect a physical death. But because they were brought back to spiritual life by the Lord and his gospel, they will go to be with the Lord should their physical body die. They will not go to hell, so to speak, as unbelievers. There is no second death after the natural death for believers. Once a person is born again by believing the good news, they become part of a royal priesthood, so to speak, and they rule and reign spiritually with Christ, being seated in heavenly places with him, even as they go about their 'ordinary' lives, so to speak (and for lack of a better term). Since they have come to believe, the time that they are now living in Christ, with him in the spirit, is said to be a figurative thousand years. This does not mean a literal thousand years but is a term describing the complete or full time. A true believer never really dies after being born again, although their physical body may grow old and die from whatever means. Who they actually are never really dies from the point of believing in Christ. They are a part of Christ.
"he that believeth in me, though he were dead, yet shall he live: And whosoever liveth and believeth in me shall never die. Believest thou this? "
"Blessed and holy is he that hath part in the first resurrection: on such the second death hath no power, but they shall be priests of God and of Christ, and shall reign with him a thousand years. "
The second idea that you mention, the idea that of animal sacrifices are continuing, as a part of the Lord's plan for the future, is, in my opinion, not the case. Whenever the mention of animal sacrifices occurs in a future sense in the Bible it most likely simply parable language for Christ's sacrifice. Christ's sacrifice will always be available to cover sins. The animal sacrifice will, in that parable sense, never be taken away for believers. There is a place in Daniel where sacrifice will be cut off, but this is most likely referring to Christ's sacrifice not being available to a particular group of unsaved persons (or possibly alluding even to Christ sacrifice on the cross). It is not talking about religious rituals that will be conducted or suddenly stopped, like the slaughter of a physical animal. That is my opinion.
