The same way we are today, through grace by faith. The only difference was the revelation of Christ was not yet complete.
I get the distinct impression that they were not actually saved until new testament times. Did any man actually get to heaven before the man, Jesus?
I think being saved and getting to Heaven are two different things. When we are saved we don't immediately go to Heaven. There is time as we are sanctified through the working of the Holy Spirit.
I believe they were saved, but I'm not sure they went to Heaven until after Christ went there first. I probably shouldn't guess further until I read up some more on it first.
When we are absent from the body, do we not go immediately into the presence of the Lord? And if so, then is not the Lord in Heaven?
THE BIBLE SAYS: Romans 16 25Now to him who is able to establish you by my gospel and the proclamation of Jesus Christ, according to the revelation of the mystery hidden for long ages past, 26but now revealed and made known through the prophetic writings by the command of the eternal God, so that all nations might believe and obey him--
Thank you for your good thought. I believe it is very close to correct, because Abraham believed God and it was credited to him as righteousness. However, I think the mystery is the gospel that applies to all the world, and that that is what is different. It is now a time of grace, when before it wasn't.