Heb 13:8 Jesus Christ the same yesterday, and to day, and for ever.
There was a time when God required animal sacrifices. There was a time when God did not require animal sacrifices. Then there came a time when Jesus Christ Himself became the living sacrifice. You see, Heb 13:8 is talking about Jesus Christ's sovereignty never changing, not a message (gospel) never changing.
Crusader:
You should know better than to make such statements. THE GOSPEL IS NOT AN EVER CHANGING MESSAGE BUT AN EVERLASTING PERSON! What exactly is the Gospel if not Jesus Christ Himself. He is the Bread of Life, the Water of Life, the Resurrection and the Life, the Way, the Truth, and the Life, Everlasting Life, the True God and Eternal Life. He, THE PERSON, is the Gospel. He, THE PERSON, died for our sins according to the Scriptures, and rose again the third day according to the Scriptures. The message is THE PERSON AND FINSIHED WORK OF CHRIST FOR OUR REDEMPTION.
IOW just as Christ is "from everlasting to everlasting", the Good News is an "everlasting Gospel". How do we know this? Because it is "according to the Scriptures". The Gospel was first preached to Adam (Gen. 3:15). It was also preached to Abraham (Gal. 3:

. It was also preached to Israel in the wliderness (1 Cor. 10:1-4; Heb. 4:1,2). The everlasting Gospel will also be proclaimed during the Great Tribulation:
"And I saw another angel fly in the midst of heaven, HAVING THE EVERLASTING GOSPEL TO PREACH UNTO THEM THAT DWELL ON THE EARTH, and to every nation, and kindred, and tongue, and people, saying with a loud voice, Fear god and give glory to Him; for the hour of His judgment is come; and worhsip Him that made heaven, and earth, and the sea, and the fountains of waters." (Rev. 14:6).
Animal sacrifices pre-figured the Lamb of God and that was their purpose. They were the "shadows" and "types". The reality is Christ. So Heb. 13:8 is NOT talking about Christ's sovereignty but His IMMUTABILITY -- "I am the LORD, I change not". Because He does not change the Gospel was already in the mind of God BEFORE the foundation of the world (1 Pet. 1:20) but was MANIFESTED in these last times for the salvation of all mankind (1 Pet. 1:20).
If the Gospel could change from age to age, then Hebrews 11 would not speak of justification by faith (Heb.11:7) long before Christ was crucified. Abel, Noah, Abraham, Sara, Isaac, Jacob, Joseph, Moses, Joshua, Rahab, Gideon, Barak, Samson, Jephtha, Samuel, David and all the prophets, as well as all OT saints were justified by faith the same as we are today: "And these all, HAVING OBTAINED A GOOD REPORT THROUGH FAITH, received not the promise: God having provided some better thing for us, that they without us should not be made perfect." (Heb. 11:39,40).
This "promise" is the Holy Spirit (Acts 2:38,39) and Christ (Acts 3:12-26). During those three days and three nights between the crucifixion and the resurrection of Christ, the OT saints did receive the promise of eternal life through Christ and were made "perfect". Therefore they were taken up with Christ after His resurrection (Eph. 4:8-10) as resurrected saints (Matt. 27:51-53) and are now with Christ in Heaven (Heb 12:22-24):
But ye are come unto mount Zion, and unto the city of the living god, THE HEAVENLY JERUSALEM, and to an innumerable compnay of angels, to the general assembly and Church of the firstborn, which are written in Heaven [NT saints], and to God the Judge of all, and TO THE SPIRITS OF JUST MEN MADE PERFECT [OT saints], and to Jesus the Mediator of the New Covenant, and to the blood of sprinkling, that speaketh better things than that of Abel".