I think I know what writings of Paul you are referring to and since I have discussed these verses with Christians innumerable times, I already have my interpretation written up and saved in a Word document.
The following is what I believe. In
1 Corinthians 15:12-22, Paul was referring to a spiritual resurrection. That Jesus was raised up means His spirit was resurrected; brought back to life. If Christ’s spirit was not brought back to life, then your faith would be in vain and you would still be in your sins.
22 For as in Adam all die, even so in Christ shall all be made alive means that all shall be made spiritually alive, not physically rise and be alive in bodies. That does not mean Jesus’ soul (spirit) was brought back to life (because the soul cannot die, so it does not need to be brought back to life); it means that the Cause of Christ (what He taught and represented) were brought back to life after three days... Had it NOT been brought back to life you would still be in your sins because it was the Cause of Christ that needed to be brought back to life in order to save people from their sins. People needed to get the Gospel message that Jesus taught and the disciples needed to carry that far and wide. Their faith in Jesus needed to be renewed (resurrected) after Jesus had died and the disciples lost all hope.
I do not believe that a physical body can come back to life after three days; that goes against all that is known by science. Moreover, even if such a miracle happened to Jesus, I do not believe that means that the physical bodies of all the believers that ever lived are going to come up out of their graves when Jesus returns.
13 But if there be no resurrection of the dead, then is Christ not risen: and
16 For if the dead rise not, then is not Christ raised: refers to rising from spiritual death, rising from the graves of ignorance of Christ, not to anyone rising from physical graves. Had the Cause of Christ not been brought back to life after three days, everyone would have remained in their sins and in spiritual death.
I believe that
26 The last enemy that shall be destroyed is death refers to spiritual death. The physical body was never designed to live forever, but the soul is immortal so it can never die. Those souls who believe in Jesus have eternal life (everlasting life) because they are near to God; other souls who are veiled from God continue to exist in the spiritual world after their physical body dies, but, in comparison with the holy existence of the children of the Kingdom of God, they are nonexistent because they are separated from God.
Thus I believe that eternal life refers to
a quality of life, gaining the rewards of the heaven, which are peace, the spiritual graces, the various spiritual gifts in the Kingdom of God, the gaining of the desires of the heart and the soul, and the meeting of God. Eternal life does not refer to continuance or duration of life, since all souls live forever.
John 3:16: For God so loved the world, that he gave his only Son, that whoever believes in him should not perish but have eternal life.
John 3:36 He that believeth on the Son hath everlasting life: and he that believeth not the Son shall not see life; but the wrath of God abideth on him.
John 17:3 And this is life eternal, that they might know thee the only true God, and Jesus Christ, whom thou hast sent.
1 John 5:13 I write these things to you who believe in the name of the Son of God that you may know that you have eternal life.
John 5:24 Verily, verily, I say unto you, He that heareth my word, and believeth on him that sent me, hath everlasting life,and shall not come into condemnation; but is passed from death unto life.
John 11:25-26 Jesus said to her, “I am the resurrection and the life. He who believes in Me, though he may die, he shall live. And whoever lives and believes in Me shall never die. Do you believe this?”
John 4:13-14 Jesus answered and said unto her, Whosoever drinketh of this water shall thirst again: But whosoever drinketh of the water that I shall give him shall never thirst; but the water that I shall give him shall be in him a well of water springing up into everlasting life.