If Jesus died spiritually, then how could he have gone to Paradise?
This question is based off of an assumption that the spiritually dead could not go to “Paradise.”
This, however, overlooks the fact that sins were not taken away until the atonement was completed (Hebrews 10:1-4). While the OT saints had life, they only had it in view of the cross of Christ. Under the Law they were still considered spiritually dead. Notice these passages:
"I was alive once without the law, but when the commandment came, sin revived and I died. And the commandment, which was to bring life, I found to bring death" (Romans 7:9-10).
"O wretched man that I am! Who will deliver me from this body of death? I thank God - through Jesus Christ our Lord! So then, with the mind I myself serve the law of God, but with the flesh the law of sin" (Romans 7:24-25).
“Who also made us sufficient as ministers of the new covenant, not of the letter but of the Spirit; for the letter kills, but the Spirit gives life. But if the ministry of death, written and engraved on stones, was glorious, so that the children of Israel could not look steadily at the face of Moses because of the glory of his countenance, which glory was passing away” (2 Corinthians 3:6-7).
Since the law could never sufficiently deal with sin, it could never restore the fellowship with God that was lost in Adam. The Old Law was a personification of that death. Consider this: the temple was where the presence of God was, but nobody could go into the Most Holy Place except for the High Priest once a year. Also, they could grow the perfect crops and raise the best livestock, but those offerings could never – no matter how good they were – deal with their sin problem. It is along this line of thinking that Paul said, “Moreover the law entered that the offense might abound. But where sin abounded, grace abounded much more” (Romans 5:20).
So, everyone under the Law died in a state of spiritual separation because of man’s inability to follow the law perfectly. The difference lies within if they tried to keep the law or not. One group was destined to rise to eternal life, but the other was destined to shame and everlasting contempt (Daniel 12:2) Therefore, Christ could give His soul as an offering and still go to “Paradise” because of His perfect keeping of the Law.