Faith saved them from the 2nd death, but they were not purified or rather justified so they could go into God's presence.
Rom 3:20 because by the works of the Law no flesh will be justified in His sight; for through the Law comes the knowledge of sin. and Acts 13:39 and through Him everyone who believes is freed from all things, from which you could not be freed through the Law of Moses.
Faith was not a free pass into the presence of God. Men lost their lives for mishandling the Ark and for offering profane fire and for other things as well. Moses was with God but God hid His face from Moses. The Law provided for the same sacrifices year after year but could never bring the worshippers to perfection for all time. (Heb 10) Then it goes on to say that God did not delight in sacrifices and whole offerings although the Law prescribed them.
verse 10, it is by the will of God that we have been consecrated, through the offering of the body of Jesus Christ once and for all. Verse 13 For by one offering, He has perfected for all time those who are thus consecrated. Verse 19 So, my friends, the blood of Jesus makes us free to enter boldly into the sanctuary by the new, living way which He has opened for us through the curtain, the way of His flesh.
Before the Veil of the Temple was torn in two, the people whether living or dead had no direct access to the Living God Almighty. This is why the veil between the Holy of Holies and the Holy was torn from top to bottom opening the way for man to come into God's presence. Not flesh and blood to go into His presence. (Cor 15) But, for the souls of men to be justified and sanctified to go into God's presence.
The OT saints were prisoners per se' in paradise because they could not go into God's presence (Heaven). They had not been consecrated by Jesus' perfect sacrifice yet. But when He willingly laid down His life for us, His perfect blood sacrifice satisfied the Law's requirement in our stead and thus He freed the captives and He conquored death by rising from the dead. It was a legal thing set up by God.
Those saved before the Cross were saved by God's promise of the Cross and those saved after were saved by the literal blood of Jesus. (Of course by faith and belief!!)
The Law required blood sacrifice and yet, there was no blood perfect enough to cover, pay for and release a human from his sins until Jesus' perfect sacrifice whereby God was satisfied that the Law was fulfilled. J
esus is the door into heaven. He said so Himself.
Matthew 7:8 For everyone who asks receives, and the one who searches finds, and to the one who knocks, the door [ Lit knocks, it] will be opened.
Matthew 25:10 "When they had gone to buy some, the groom arrived. Then those who were ready went in with him to the wedding banquet, and the door was shut. [ Mt 22:2; Lk 13:25;]
John 10:1 [ The Ideal Shepherd ] " I assure you: Anyone who doesn't enter the sheep pen by the door but climbs in some other way, is a thief and a robber.
John 10:7 [ The Good Shepherd ] So Jesus said again, " I assure you: I am the door of the sheep.
John 10:9 I am the door. If anyone enters by Me, he will be saved and will come in and go out and find pasture.
Until Jesus laid down His life as perfect sacrifice, there was no door into Heaven by which mankind could walk through into God's Holy presence after Adam sinned. It is my understanding that Paradise was the place of comfort designed as a place for the OT saints to go while waiting for God's promised Son, the Messiah, to appear and follow through with God's perfect will.