Paul, I believe, speaks to that, is it in Hebrews? I'll check, their faith being counted as righteousness....among other things.
Romans 4:2-4
If, in fact, Abraham was justified by works, he had something to boast about--but not before God. What does the Scripture say? "Abraham believed God, and it was credited to him as righteousness." Now when a man works, his wages are not credited to him as a gift, but as an obligation.
Romans 4:12-14
And he is also the father of the circumcised who not only are circumcised but who also walk in the footsteps of the faith that our father Abraham had before he was circumcised. It was not through law that Abraham and his offspring received the promise that he would be heir of the world, but through the righteousness that comes by faith. For if those who live by law are heirs, faith has no value and the promise is worthless . . .
John 5:46 “If you believed Moses, you would believe me, for he wrote about me.”
Hebrews 11:23-25
By faith Moses' parents hid him for three months after he was born, because they saw he was no ordinary child, and they were not afraid of the king's edict. By faith Moses, when he had grown up, refused to be known as the son of Pharaoh's daughter. He chose to be mistreated along with the people of God rather than to enjoy the pleasures of sin for a short time.
"In the beginning was the Word and the Word was with God and the Word was God. He was in the beginning with God...and the Word became flesh and dwelt among us." (John 1:1-2, 14)
Christ has always been, even before the world was made and because God anticipated the choice that man would make to turn from Him, He made provision for his redemption. The faithful under the old covenant did not experience Him in the same way, but they believed in God's promises. God spoke to His people throughout time and those who believed trusted His way. Job, the oldest book in the Bible, was not written in Job's time. For many generations, people did not have the written Word and yet God spoke to them. He gave them what they needed upon which to base their faith. In that context, this statement of Job's is quite profound and revealing:
"I know that my Redeemer lives, And at the last He will take His stand on the earth." (Job 19:25)
Neither did Abraham have the benefit of the written Scriptures and yet when God told him that he would have a son in his old age with his wife well past the age of child-bearing the scripture says that
"he believed God and He counted it to him as righteousness." (Genesis 15:6)
"For with the heart man believeth unto righteousness..." (Romans 10:10)
Later when God asked Abraham to take his only son, the son of that promise, and offer him up as a sacrifice, he obeyed. I expect that on his way to the mountain that God had showed him that he agonized over the testing of his faith as any parent would, and yet deep in the heart of Abraham he knew that the God who had fulfilled His promise in the birth of Isaac had also promised that He would make of Isaac a great nation through which all the nations of the earth would be blessed (the promise of the coming of Christ), a promise which could not be fulfilled if Isaac were dead. So Abraham went forth to do God's will having faith that God was good for His word and would do something even if it meant raising Isaac form the dead.
Though the King James version is not the best translation from the original in many instances, there is one verse here where it is absolutely right. When Isaac questioned his father of the whereabouts of the lamb for the burnt offering, Abraham said:
"...God will provide himself a lamb..." (Genesis 22:8a)
David also recognized God's hand of deliverance:
"For great [is] thy mercy toward me: and thou hast delivered my soul from the lowest hell." (psalm 86:13)
I think this is one place the Catholics have it right (insofar as Catholic doctrine is different than much of protestant doctrine). In the writings of Dante and C.S. Lewis I see this picture of hell as various "levels", not all of which are equal. Dante paints the upper levels of hell as being almost carefree, albeit still separated from God. The writings of the Old Testament are filled with promise and hope of redemption and some level of recognition of the savior "slain before the foundation of the world" (Rev. 13:8b). When Christ was crucified he descended to the place of the dead and released those who had died in faith. On the day of Pentecost when Peter was filled with the Holy Spirit and spoke of the fulfillment of the prophecies in the death and resurrection of Christ he quoted these words of David:
"I foresaw the Lord always before my face, for he is on my right hand, that I should not be moved: Therefore did my heart rejoice, and my tongue was glad; moreover also my flesh shall rest in hope: Because thou wilt not leave my soul in hell, neither wilt thou suffer thine Holy One to see corruption." (Acts 2:25-27)
Finally, Christ Himself speaks to John in Revelation 1:18 saying:
"I am he that liveth, and was dead; and, behold, I am alive for evermore, Amen; and have the keys of hell and of death."
It is reasonable to draw from these verses, and many others, that part of Jesus' work of the cross was to descend to the dead and release those whose faith had been their righteousness.