Before Christ died, the Devil had the power of death and Hades (Heb 2:14). Jesus took the power of death and Hades from the Devil when He emerged from the grave (Rev 1:18, Acts 2:24). Until Christ acquired the power of death and Hades, all souls of the dead were in the possession of the Devil. They were his prisoners (Job 3:18, Ps 142:7). As you point out, God did not permit the saints to be tortured (Lk 16:25), but they were cut off from God and were prisoners in the Devil’s realm. Jesus said that no man had ascended up to heaven where the Father is (Dt 4:39), except the Son of Man who came down from heaven (Jn 3:13). However, Paradise is in heaven (II Cor 12:2-4, Rev 2:7), not Hades. It appears to be the same thing as the Garden of God (Ezek 28:13, Rev 2:7). Therefore, since men who died did not go to heaven, they also did not go to Paradise since it is in heaven. When Jesus died, He did not go into heaven, but into the Devil’s realm in Hades (Acts 2:27) where He wrested the power of death and Hades from the Devil (Mt 12:19, Mk 3:27, Lk 11:21-22).
What, then did Jesus mean when He said, “Today, thou shalt be with me in Paradise” (Lk 23:43)? It has commonly been interpreted to mean that Jesus went to Paradise when He died. Since Paradise is in heaven, He clearly did not. His soul went to Hades into the Devil’s realm (Acts 2:31). I believe that Jesus promised the thief that because of what the thief had done that day that salvation was come to him and that He would be with Christ in Paradise at some future time. “Today” in the sense that Christ used it in Lk 23 is in the sense of “now” (cp. Lk 19:9). Essentially Jesus said, “Because of what you have done here and now, you will be with me in Paradise”.
When men die, their souls return into the custody of God who permits the angels to dispose of the soul in accordance with its character (Lk 16:22). However, before the cross, nobody went to heaven when they died (Jn 3:13). The Devil had the power of death, and even the righteous went into his custody. That is why NT saints are so much better off than the OT saints at death; we go to be with Christ when we die (Php 1:23, II Cor 5:8-9). Before that, all they had to look forward to at death was the gloominess of the Devil’s prison where they were cut off from God (Ps 88:3-6, Job 33:30). Jesus came to set these righteous souls free (Isa 61:1, Lk 4:18-21) and to take them into heaven (Eph 4:8) where we find them now (Rev 6:9, I Thes 4:14, Rev 20:4). It was when Jesus ascended on high that He took the soul of the thief from Hades with Him into heaven as He had promised.
There is no doubt that the Father was with Christ during most of His ordeal, but Jesus never said that God would be with Him always. When He died, Jesus was made to be sin for us (II Cor 5:21). Sin separates from God (Isa 59:2). If Jesus was made to be sin, then it seems perfectly logical for Jesus to be separated from God as a consequence of being made sin for us. I do not see how He could avoid being separated from God if He truly became sin for us. Like the scapegoat was separated from God by being sent into the wilderness unto Azazel (Lev 16:10 ASV), even so Christ as our scapegoat was separated from God for a short time. “He was pierced for our transgressions, he was crushed for our iniquities; the punishment that brought us peace was upon him, and by his wounds we are healed” (Isaiah 53:5 NIV). Not long before He died, Jesus was made to be unholy for us and suffered separation from God (Mt 27:46), and as a consequence of being made unholy, he suffers inferiority to God in eternity (I Cor 15:28). God raised Him from the dead (Acts 2:32), but there were permanent consequences of Jesus sacrifice. Jesus emptied Himself of His equality with God when He became a servant (Php 2:6-7). When He ascended back to the Father, God permitted Jesus to rule on the Father’s throne until the resurrection of the dead (Acts 2:34-35, Acts 3:21, I Cor 15:24-26), at which time Jesus will then sit on the throne of HIS glory (Mt 25:31, Rev 3:21), the throne of His father David (Lk 1:33).
The Bible does not say that Jesus became a sinner. It says He became sin. Like the high priest laid the sins of Israel onto the scapegoat and sent it into the wilderness (Lk 16:20-21), even so God laid the sins of men upon Christ (Isa 53:6), God’s Lamb (Jn 1:36) [of the sheep or goats–Ex 12:5] , and sent Him into the wilderness of Hades. The scapegoat did not become a sinner, but it became sin and bore the sins away from Israel. Jesus became sin for us and bore our sins away from us.
Now let’s consider the sacrifice of Christ. His sacrifice fulfilled the type of the sacrifices of the two sin goats that were sacrificed on the Day of Atonement. When one of the sin goats was slain, the blood of that slain goat was sprinkled on the altar to atone for the sin of the people (Lev 16:15-16). The other goat was sent into the wilderness. Jesus fulfills the types of both the scapegoat and the sin goat. He bore our sins away from us, and His sprinkled blood atones for sin. However, the blood of a sacrifice was conditional. In order for something to be made holy, the object that was to be made holy (sanctified) had to be sprinkled with the cleansing blood (Lev 8:30). Our souls are sprinkled with the blood of Christ at baptism (Heb 10:22). Like the priest had the blood of cleansing in his hand but it didn’t cleanse anything until he sprinkled it on something, even so Christ, our High Priest, has the blood of cleansing in His hand, but it is only applied to those who come to receive it. God has received the price of redemption for the souls of men and His justice is satisfied, but the payment for the debt of sin is only applied to souls that wish to receive it. The terms of redemption are clearly spelled out in the NT. They are HBRCB. When these terms are met, the blood is applied (sprinkled) on his heart and redemption/sanctification is the result (Acts 2:38, Mk 16:16). Other than that, God has not promised a man anything regarding salvation. As you can see, the process involves man’s obedience and is not just an arbitrary act of a sovereign God.
I do not see how Jesus paying the full price for sin invokes Calvinism. If Jesus, our High Priest (Heb 4:14), has the cleansing blood (Heb 9:12, Rev 1:5) and only applies it to those who come seeking it (Rev 22:17), then salvation is not unconditional and is not arbitrary. Any who come may be cleansed, but they come of their own free will. The fact that Jesus was made to be sin for us and went to the wilderness of Hades, as the scapegoat type requires, does not mean that men are saved by the arbitrary action of God. It is not twisting the scriptures to believe what they say and they say that Jesus went to Hades (not Paradise), was forsaken by God, and was made to be sin for us.