Before the worldly birth of the Lord, what did people do for salvation and eternal life? I wonder if one can make an inference from Adam and Eve- who seemed not to have experienced time in the garden- that souls were meant to be eternal, yet of course bungled it from the start. The proto-evangelium indicates a plan for correction and reconciliation eventually. Obeying the laws of God were required, yet no one could satisfy the condition, so a new covenant was made. I believe that if Jews could have lived by the law they would have been fine with God. So I believe that people like Isaiah and Hosea were saved though the majority wasn’t.
Philo of Alexandria was an interesting philosopher who was influenced by the Kabbalah about the time the 70 were translating the Septuagint in Alexandria Egypt. He has all sort of mentions of various heavens- rather comparable in some ways to Pierre Teilhard de Chardin. I try not to get caught up much in metaphysics for cosmology regarding heaven and where it is- after all Einsteinian general relativity illustrates the problems with that. I would say something like- it is with God rather than it is 1000 miles east and 2000 up. People have pointed out several examples of people that went unto God (i.e. Noah, Enoch) and I believe that sort of thing indicates that God has given them eternal life. Back in the day those people weren’t very much into abstract spatio-temporal concepts. I believe that since God is eternal souls are too. The fall of mankind resulted in them being downloaded into the temporal world in order to contain them because they were full of sin- missing the mark of obedience to the will of God. The temporal world has thermodynamics and entropy…God makes those things and Universe as a subset of a meta-set I suppose. Temporality is not forever.
Genesis 15:6 King James Version (KJV)
6 “And he believed in the Lord; and he counted it to him for righteousness.”