I often get the question, “How were people saved in the Old Testament?” To answer this question, I usually follow the Apostle Paul’s logic in Romans 4.
When God chose Abraham to father a nation and promised to one day bring salvation into the world through him, Abraham and his wife were already in their 70s. They continued to be childless until they were 90 years old.
Still, “[Abraham] believed, hoping against hope, so that he became the father of many nations according to what had been spoken: So will your descendants be” (Romans 4:18 CSB).
Abraham didn’t just believe in God in general; he believed a specific promise God had made, and he adjusted his life around it.
From that point on, Abraham started walking around with the expectation that he was having kids soon. He built a nursery and started picking out baby names, all while scouting out land for a new nation.
And, because Abraham “was fully convinced that what God had promised, he was also able to do … it was credited to him for righteousness” (Romans 4:21–22).
Tim Keller says, “Saving faith is not believing that God is there. Further, it is not believing in a God who saves. It is believing God when he promises a way of salvation by grace.”
Faith’s object is the promise of God. Faith is believing that God will do what God said he’d do and adjusting your life around that promise.
Paul goes on to make the bridge to us: “Now ‘it was credited to him’ was not written for Abraham alone, but also for us. It will be credited to us who believe in him who raised Jesus our Lord from the dead. He was delivered up for our trespasses and raised for our justification” (Romans 4:23–25).
Just like Abraham believed God would send a son that would bring salvation into the world as he was promised, we believe that Jesus is that son. The resurrection, Paul says in verse 25, was proof that God had accepted Jesus as the payment for our sins.
So, when we believe in the resurrection, we are saying, “I believe it worked! I believe Jesus accomplished what he said he accomplished! I believe when Jesus said ‘it is finished’ that it was finished.”
When we confess that and then live as if we believe in it, it is credited to us as righteousness.
Our faith, you see, is the same as Abraham’s: We both believe that God keeps his promise to send salvation. Abraham believed that God would send it; we believe that he has sent it.
People in the Old Testament were saved just like us: They looked forward to the cross; we look backward at it. The direction is different, but the object is the same.