Doctrines Concerning
Salvation
A. That God's plan of salvation has never changed and is the only means of reconciliation between God and man.
Gen 3:15
And I will put enmity between thee and the woman, and between thy seed and her seed; it shall bruise thy head, and thou shalt bruise his heel.
2Co 5:18
And all things are of God, who hath reconciled us to himself by Jesus Christ, and hath given to us the ministry of reconciliation;2Co 5:19
To wit, that God was in Christ, reconciling the world unto himself, not imputing their trespasses unto them; and hath committed unto us the word of reconciliation.Personal Opinion:
I hardly see how the passages cited apply to the point. So I am still left with the question of where in scripture the Old Testament Saint could point to for God's plan for their salvation prior to the time of Isaiah or maybe David.
On second thought, I think there is a passage in Job which might apply and Job, in my opinion goes way back maybe prior to Abraham but not Noah.
Now Noah of course predated any written word so maybe the answer is those very early Old Testament Saints just were expected to muster up their faith based on the spoken testimony of Godly prophets.