Christ is the lamb of God slain from the foundation of the world (6 days that he did literal work out His plan ) Not from the shadow as a one time demonstration that points to the eternal . The demonstration of the lamb of God beginning in the garden of Gethsemane, moving to the cross and finally the tomb was over when Jesus said . . It is finished. Jesus the Christ not Jesus the Son of man as shadow purified Abel in Genesis having favor on him and not Cain . The first recorded apostle and martyr .
Jesus didn't get slain before he came to earth and was slain.
You misunderstand that scripture.
Here are better translations:
Revelation 13:8 NET Bible and all those who live on the earth will worship the beast, everyone whose name has not been written since the foundation of the world in the book of life belonging to the Lamb who was killed.
New Heart English Bible All who dwell on the earth will worship him, everyone whose name has not been written from the foundation of the world in the Book of Life of the Lamb who has been killed.
New American Standard 1977 And all who dwell on the earth will worship him, everyone whose name has not been written from the foundation of the world in the book of life of the Lamb who has been slain.
American Standard Version And all that dwell on the earth shall worship him, every one whose name hath not been written from the foundation of the world in the book of life of the Lamb that hath been slain.
Darby Bible Translation and all that dwell on the earth shall do it homage, [every one] whose name had not been written from [the] founding of [the] world in the book of life of the slain Lamb.
There is no such thing as Jesus being slain twice.
Jesus died ONCE and for ALL.
It is the BOOK AND THE PLAN OF SALVATION that was written before the foundation of the world.
Revelation 17:8 The beast that thou sawest was, and is not; and shall ascend out of the bottomless pit, and go into perdition: and they that dwell on the earth shall wonder, whose names were not written in the book of life from the foundation of the world, when they behold the beast that was, and is not, and yet is.
Ephesians 1:4 According as he hath chosen us in him before the foundation of the world, that we should be holy and without blame before him in love:
Carnal ordinances used in ceremonies as shadow of the eternal not seen in parables .They cannot not not bring a person any closer to God whether they performed them or not .
The people had to do the works of the law, which are the purification works. Those are the works of the law. The people were commanded to do them. Not obeying God and doing them made one an enemy of God. It was why the Gentiles were called enemies.
Colossians 2:13 When you were dead in your sins and in the
uncircumcision of your flesh, God made you alive with Christ. He forgave us all our sins,
Ephesians 2:11 Therefore remember that formerly you who are
Gentiles in the flesh and called uncircumcised by the so-called circumcision (that done in the body by human hands)— 12 remember that at that time
you were separate from Christ, alienated from the commonwealth of Israel, and strangers to the covenants of the promise, without hope and without God in the world. 13 But now in Christ Jesus you who once were far away have been brought near through the blood of Christ.