How can the Old Testament people be saved if there was no Jesus then?

This is a great question, one that is important to understand as we understand who Jesus is and what He did. Prior to answering this question though, I think there is some important truths to remember:
1) God is outside of time. Therefore what he does in an instant could actually play itself out over thousands of years.
2) It says (referring to Jesus) in Hebrews 13:8 “I am the same yesterday, today, and forever”.
When we exist inside of time, it’s hard to understand a God who is outside of it. Therefore, we accept it by faith. Believing this takes us a step closer to seeing how Jesus’ death can be the central act of all history. When sin entered the world through Adam, a plan of equivalent payment had to be made. This payment would be so great, and such an act of Love, that it would fulfill redemption of all people for all times. Therefore when Jesus died as the substitutionary atonement…it was not just for the sins that came after him, it was for the sins of everybody, who has ever lived.
2 Corinthians 5:14-15 addresses this well:
For the love of Christ controls us, having concluded this, that one died for all, therefore all died; and He died for all, so that they who live might no longer live for themselves, but for Him who died and rose again on their behalf.
Our first thing to note then is that all were included in the payment accomplished by Jesus’ death.
Another point of interest however is answering the question: was Jesus present? Many scholars, as they seek to understand the role of the trinity throughout time and text, point to names often used for either Father, Son, or Holy Spirit. For example, when a metaphor of dove is used, we assume that this is referring directly to the Holy Spirit. In a simple word study, we see the title of “Lord” in the New Testament as the primary title to depict Jesus’ role and authority. Interestingly enough, Lord is used often throughout the Old Testament in specific settings or stories. So where we know Jesus was not there in flesh, the spirit of the Lord is active. Most scholars refer to this “spirit of the Lord” as God the son, or the spirit of Jesus, as present. (example: Genesis 10-12)

Finally, I find it very unique that the disciples in the gospels knew what they were looking for in a messiah. Meaning: The gospel is explained thoroughly in the Old Testament! People awaited a Messiah who would take away their sins, being the ultimate payment against death. They lived in the same mode of redemption we do.

In summary, these are 3 good places to start. Christ’s death, by view and plan of God, paid for the sins of all because that is the way he purposed it. Secondly, if Jesus is the same yesterday, today, and forever, than we see his fingerprints not just in the gospels, but also throughout the Old Testament. And last, we trust that to be able to expect the Messiah, they had to know something of what he was going to be like. The Old Testament is as much a purposed account for the gospel as the New Testament is.

~Deep thoughts by a Shallow guy~
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