If after the sin of Adam and Eve no people had sanctifying grace until Jesus came, how could Old Testament people get to heaven and be saints?
All human salvation comes in and through Jesus Christ. Those in the Old Testament who were saved were justified (received sanctifying grace) by means of their belief in the coming, future Messiah. Of course, they could not enter heaven until Christ died and rose from the dead. It was to the just of the Old Testament (1 Peter 3:19) that Christ’s soul went when “He descended into hell.” They accompanied Him when He ascended into heaven. The justified of the Old Testament were baptized into Christ by a baptism of desire, and in that way received sanctifying grace.