Israel’s atonement offerings specified by the Law were shadows that lead to the reality of Jesus’s one, all-sufficient, atonement sacrifice. The Apostle Paul wrote,
Hebrews 10:1,2, 4 (NKJV), 1 “For the law, having a shadow of the good things to come,. . . can never with these same sacrifices, which they offer continually year by year, make those who approach perfect. 2 For then would they not have ceased to be offered? For the worshipers, once purified, would have had no more consciousness of sins. . . 4 For it is not possible that the blood of bulls and goats could take away sins.”
Paul continued to explain that Jesus fulfilled the Law through His sacrificial death.
Hebrews 10:8-10 (ESV), 8 “When he (Jesus) said above, ‘You have neither desired nor taken pleasure in sacrifices and offerings and burnt offerings and sin offerings,’ these are offered according to the law, 9 then he added, ‘Behold, I have come to do your will.’ He does away with the first in order to establish the second. 10 And by that will we have been sanctified through the offering of the body of Jesus Christ once for all.” Jesus set aside the typical sacrifices that he (Jesus) might fulfill the antitype, the real sacrifice for sins.
Salvation can only be obtained through the blood of Jesus. 1 John 1:7 (NKJV), “…the blood of Jesus Christ His Son cleanses us from all sin.” Typical sacrifices could never bring salvation. Acts 4:12 (ESV), “And there is salvation in no one else, for there is no other name under heaven given among men by which we must be saved.”
So, the question arises, ‘How did people who lived and died before Jesus gain salvation?’ During their lifetime, they died in their sins. But we know God’s plan includes the opportunity for salvation for all (including the dead). 1 Timothy 2:4-6 (NKJV), 4 “who (God) desires all men to be saved and to come to the knowledge of the truth. 5 For there is one God and one Mediator between God and men, the Man Christ Jesus, 6 who gave Himself a ransom for all, to be testified in due time”.
The “due time” for all men to come to a knowledge of the truth will be in the earthly resurrection during Christ’s reign. The purpose of Christ’s reign is to teach mankind righteousness, to forgive their sins, and to give them the opportunity to receive eternal life. Jeremiah 31:33-34 (ESV), 33 “For this is the covenant that I will make with the house of Israel after those days (after Armageddon), declares the LORD: I will put my law within them, and I will write it on their hearts. . . 34 (then) they shall all know me, from the least of them to the greatest, declares the LORD. For I will forgive their iniquity, and I will remember their sin no more.’”
All nations will eventually come under this blessed covenant as well. (See Isaiah 2:2-4.) Only the unwilling and incorrigible will be cut off from life and die the second death.