THE CLAIM

1)The Bible defines two body types, natural and spiritual. God and the angels are spiritual bodied beings, while all other beings are physical. The main difference between the two types is longevity. Spiritual bodies are immortal, while natural bodies will perish. Also, pain is necessary for natural bodies to recognize when they're in harm's way. Spirits are indestructible, and thus need no pain.


The Biblical Proof


The Bible defines two body types, natural and spiritual:

There is a natural body, and there is a spiritual body. (I Corinthians 15:44)      (Genesis 3:4)

The natural body comes first and may be followed by a spiritual body:

Howbeit that was not first which is spiritual, but that which is natural; and afterward that which is spiritual. (I Corinthians 15:46)

There is never any mention of a spiritual body living in a physical body.
There is never any mention of a spiritual body living within a physical body. Man was created originally with only two differences between himself and the spiritual world beings. Those two differences were body type and knowledge of good and evil. Trees in the Garden of Eden represented each of these differences; the tree of knowledge of good and evil and the Tree of Life.

Upon eating from the tree of knowledge, man became closer to being like the angels in that he knows good from evil. The one remaining difference is body type, physical versus spiritual.

And the Lord God said, Behold, the man is become as one of us, to know good and evil: and now, lest he put forth his hand, and take also of the tree of life, and eat, and live for ever: Therefore the Lord God sent him forth from the garden of Eden, to till the ground from whence he was taken. (Genesis 3:22-23)

So one difference between natural and spiritual bodies is everlasting life.

And speaking of those who shall inherit the Kingdom of God in the world to come, Jesus states:

Neither can they die any more, for they are equal unto the angels... (Luke 20:36)

If there were two differences originally, and man gained one of those differences in the Garden of Eden, then there is only one remaining difference between man and the angels.

Indeed, Jesus tells us what one thing man must do to be saved:

Jesus answered, Verily, verily, I say unto thee, Except a man be born of water and of the Spirit, he cannot enter into the kingdom of God. That which is born of the flesh is flesh; and that which is born of the Spirit is spirit. Marvel not that I said unto thee, Ye must be born again.

Pain is necessary for natural bodies to recognize when they're in harm's way. Spirits are indestructible, and thus need no pain. Describing Christians who will be born again as spiritual beings, the Bible proclaims:

And God shall wipe away all tears from their eyes; and there shall be no more death, neither sorrow, nor crying, neither shall there be any more pain: for the former things are passed away. (Revelation 21:4)