I Corinthians 15:35 But someone may ask, "How are the dead raised? With what kind of body will they come?" 36 How foolish! What you sow does not come to life unless it dies. 37 When you sow, you do not plant the body that will be, but just a seed, perhaps of wheat or of something else. 38 But God gives it a body as he has determined, and to each kind of seed he gives its own body. 39 All flesh is not the same: Men have one kind of flesh, animals have another, birds another and fish another. 40 There are also heavenly bodies and there are earthly bodies; but the splendor of the heavenly bodies is one kind, and the splendor of the earthly bodies is another. 41 The sun has one kind of splendor, the moon another and the stars another; and star differs from star in splendor.
42 So will it be with the resurrection of the dead. The body that is sown is perishable, it is raised imperishable; 43 it is sown in dishonor, it is raised in glory; it is sown in weakness, it is raised in power; 44 it is sown a natural body, it is raised a spiritual body.
If there is a natural body, there is also a spiritual body. 45 So it is written: "The first man Adam became a living being"; the last Adam, a life-giving spirit. 46 The spiritual did not come first, but the natural, and after that the spiritual. 47 The first man was of the dust of the earth, the second man from heaven. 48 As was the earthly man, so are those who are of the earth; and as is the man from heaven, so also are those who are of heaven. 49 And just as we have borne the likeness of the earthly man, so shall we bear the likeness of the man from heaven.
50 I declare to you, brothers, that flesh and blood cannot inherit the kingdom of God, nor does the perishable inherit the imperishable. 51 Listen, I tell you a mystery: We will not all sleep, but we will all be changed 52 in a flash, in the twinkling of an eye, at the last trumpet. For the trumpet will sound, the dead will be raised imperishable, and we will be changed. 53 For the perishable must clothe itself with the imperishable, and the mortal with immortality. 54 When the perishable has been clothed with the imperishable, and the mortal with immortality, then the saying that is written will come true: "Death has been swallowed up in victory."
55 "Where, O death, is your victory?
Where, O death, is your sting?" 56 The sting of death is sin, and the power of sin is the law. 57 But thanks be to God! He gives us the victory through our Lord Jesus Christ. 58 Therefore, my dear brothers, stand firm. Let nothing move you. Always give yourselves fully to the work of the Lord, because you know that your labor in the Lord is not in vain. NIV
Can we FULLY understand this? Probably not. The author has chosen to merely label our spiritual "body" as imperishable. But he makes a CLEAR distinction betweent he two! Time and time again, God points out that we focus on the EXTERNAL when it is our HEART that is important. The spiritual far outweighs the physical and unlike our bodies, it will never cease to be.
This permeates our entire being. We weep and mourn when someone's physical body dies. Yet we never even notice when their soul dies. Spritual death is when we lose contact with God, and it is FAR more tragic than any physical death we can encounter.