How are the people of the old testament saved?

Question from moody radio listener: How did the people in the old testament know that they are saved or not? I know God made the relationship known like Moses, Abraham and the prophets, but without Jesus, how are the people saved in the old testament? Answer from Dr Michael Rydelnik from Moody Radio openline on Oct 24, 2015 I think the simplest way to understand salvation is people are saved the same way all the time, by grace through faith in the revealed will of God. So, it is always by God's undeserved kindness towards us, that is by grace through faith through trust. However, what is the object of trust? What are we trusting in? It is by whatever God has revealed for us to trust in. In the old testament, people were told to trust that if they sinned, and offered sacrifices, God will provide a covering for their sins and probably they received enough revelation of a coming Messiah, though they might not have known that his name is Jesus. They might not have comprehended of all the details that have been revealed to them about Jesus in the scriptures. So, if they offered the sacrifices in trust in God forgiving them and they look forward to that coming redeemer, that was their trust and their sins are forgiven. We know that those old testament sacrifices are like paying the minimum balance of the credit card and holding them off for another month but it does not deal with the principal and interest of the debt. When Jesus came, his death paid the penalty, paid the principal and interest and everything dealing with the debt. This is not only true of the case for us who believed today but even for the people in the old testament. It is Jesus' death that dealt with sin. It is Jesus's death that is the fulfilment of the old testament sacrifical system. Above answer is not word for word from Dr Michael Rydelnik.  Some words are phrased based on my own understanding of the audio clip.