1 Corinthians 15:3-7 For I delivered to you first of all that which I also received: that Christ died for our sins according to the Scriptures, 4 and that He was buried, and that He rose again the third day according to the Scriptures, 5 and that He was seen by Cephas, then by the twelve. 6 After that He was seen by over five hundred brethren at once, of whom the greater part remain to the present, but some have fallen asleep. 7 After that He was seen by James, then by all the apostles. NKJV
1 Corinthians 15:12-24 Now if Christ is preached that He has been raised from the dead, how do some among you say that there is no resurrection of the dead? 13 But if there is no resurrection of the dead, then Christ is not risen. 14 And if Christ is not risen, then our preaching is empty and your faith is also empty. 15 Yes, and we are found false witnesses of God, because we have testified of God that He raised up Christ, whom He did not raise up—if in fact the dead do not rise. 16 For if the dead do not rise, then Christ is not risen. 17 And if Christ is not risen, your faith is futile; you are still in your sins! 18 Then also those who have fallen asleep in Christ have perished. 19 If in this life only we have hope in Christ, we are of all men the most pitiable. 20 But now Christ is risen from the dead, and has become the firstfruits of those who have fallen asleep. 21 For since by man came death, by Man also came the resurrection of the dead. 22 For as in Adam all die, even so in Christ all shall be made alive. 23 But each one in his own order: Christ the firstfruits, afterward those who are Christ’s at His coming. 24 Then comes the end, when He delivers the kingdom to God the Father, when He puts an end to all rule and all authority and power. NKJV
In 1 Corinthians 15 Paul addresses the question of the resurrection. Paul had to do this as Corinth was in Greece, just a few miles from Athens, the capitol of Greek philosophical schools. They were trying to address syncretise Platonism and Christianity. Manifest in their denial of the resurrection of the body as the Christian hope in favour of Plato’s “immortality of the soul” with our soul (spirit, ghost) going to heaven. Philosophical arguments and debates arose among this assembly in their attempts to harmonize Scripture with the various Greek philosophies with which they were already familiar.
The absurdity of the Gospel to the Greek mind is illustrated by the reaction to Paul’s speech at Athens (Acts 17), where he was mocked for proclaiming the resurrection of the dead. This concept was contrary to the Platonic idea of the immortality of the soul.
Before arriving at Corinth, Paul had just delivered his powerful speech to the philosophers at Athens proving that he was indeed acquainted with Greek philosophical works (Acts 17:16-34). Arriving in Corinth, he first gave witness in the synagogue, but was quickly thrown out. At this point Jesus appeared to Him in a vision, saying “Do not be afraid, but speak, and do not keep silent; for I am with you, and no one will attack you to hurt you; for I have many people in this city” (Acts 18:9-10). Paul determined to avoid philosophy, and exclusively proclaim the Christ crucified.
This is a warning not to employ philosophical speculation beyond what has been specifically revealed in the sacred Scriptures. There is always great danger in such speculations, and it causes unnecessary and harmful strife.
Paul was illustrating that the Corinthian version of Christianity, with its syncretism with Greek philosophy, was nothing like apostolic Christianity. Highlighting this contrast was intended as a rebuke. They should not be seeking to modify Christianity to make it palatable in the intellectual arena. Rather, like the Apostles, they should embrace the ridicule for the Gospel’s apparent foolishness
The proof of Jesus’ resurrection did not rest exclusively on Paul’s testimony concerning his Damascus Road encounter with Jesus. That encounter could have been explained away in the Platonic philosophy as an encounter with Jesus’ ghost. So Paul called all of these eyewitnesses, some of whom actually handled the resurrected Jesus or saw Him eat food.
The Greek mind had great difficulty accepting the concept of the resurrection of the flesh. Are we any different today in the western world? They had been steeped in Plato’s “immortality of the soul” doctrine and his claim that the flesh was the “prison of the soul,” and that all physical substance was inherently corrupt. To the Greeks, escaping the body of flesh and ascending into the “celestial spheres” as pure “spirit” was the goal. Consequently, the idea of the resurrection of the flesh meant permanent imprisonment in inherently corrupt matter, and permanent confinement to this material creation.
If Paul and the other Apostles of Jesus were indeed mistaken about His resurrection, then believers who have died in the hope of following Jesus in their own bodily resurrection have already perished. Note that Paul did not allow for another possibility, that their souls were immortal and continued to live on outside the body. This is strong evidence that he did not believe in the “immortality of the soul” living as a spirit in heaven. Either believers died in the true hope of following Jesus in resurrection, or they already perished. Paul allowed no other option.
If the Apostles of Jesus have placed all their hope in a mistaken belief that Jesus was resurrected, and face severe persecution and even martyrdom on account of their false testimony and mistaken belief, they are indeed pitiful men.
The above is just one example of how immortality of the soul can impact what we believe and the lack of hope it brings. The Catholic Church unfortunately brought this teaching in under Constantine in the 3rd Century and it has not left the consciousness of most of the church until today and continues to effect how we view the whole counsel of scripture.