just curious....what if there is no physical body remaining ie. in the case of cremation? Will the resurrection return all the ashes together and form the physical body again? Thanks for your answer. I'm just doubtful of the bodily resurrection in terms of the afterlife. I do believe Jesus and anyone else that was raised from the dead by the power of God was a true bodily resurrection, but I'm doubtful our resurrection is going to be a bodily one because if I'm not mistaken, our resurrection of the body is a new body, a spiritual/eternal body. So in other words, I won't be walking around in heaven looking the way I did on earth. People won't see me in the form I am in now. They will see me by my spiritual body.
Somewhat ironically, these were questions--and attacks--which the ancient Greco-Roman pagans often used against Christians. They mocked belief in resurrection for a number of reasons. Broadly they attacked the doctrine of the resurrection because the Greeks tended to view physical, material reality as "lesser" or "lower" than the "higher" spiritual reality. According the Plato the physical world is actually a poor imitation of the greater reality, and that human souls are in a sense "trapped" in physical bodies. Many believed in a form of reincarnation, that the soul would go through many bodily forms until it was finally freed from this bondage of physical matter. But the other ways resurrection was attacked was by saying that if the physical body decays, returning back to dust in the earth, then how can it be raised again? They would also ask--mockingly--that if someone who lost a limb, or had a deformity, or other major physical ailment, what would happen to them, would they be raised up only to have a missing limb, or deformity, or other ailment again?
The earliest defenders of the Christian faith, such as St. Justin Martyr, specifically wrote works addressing these questions, attacks, and answered them. Justin wrote a work, though the version we have today is incomplete, specifically defending the resurrection titled On the Resurrection. In which he argues, pretty simply, that why should it be a challenge for God to raise the body and restore it entirely, even if it has fully decayed or consumed in fire, or dissolved int he sea, etc. He argued that why should it be a challenge for God to raise up the body more glorious than it was before--what may have been lacking in present shall not be lacking in the resurrection. A person born without, or who lost their legs, or arms, etc should not be lacking in the resurrection, for the body shall be perfect and glorious. The body, in all its members, shall be raised up; but we should not assume the body will function as it once did--for it has a new life, a new kind of life, a transformed existence by the power of God.
Speaking from a modern understanding, we know that the atoms which make up our bodies today are not the same atoms that made up our body when we were born--and yet it's still our body, it's still us. As we grow older, we are exchanging atoms, and our cells are dying and new cells are being made. None of the matter that makes up ourselves is the same matter that we had when we were born, and yet we are still ourselves, this body is still our body, this flesh is still our flesh, it's still our bones, our blood, our sinews, etc. So even if in the resurrection our bodies having decayed and the material elements having decomposed and have gone on to feed trees, bugs, and are now in the animals that ate the leaves etc it is still our bodies which are raised. If we can still have our bodies be our bodies, even though we have exchanged all the material elements that make up our bodies over the course of our own mortal life many times, then it should not be a difficult thing for God to raise up this same body even though it be fully decayed or dissolved or burned to ashes. The body will be raised, and also transformed. Our flesh shall be raised up, but also glorified.
@Mark Quayle is right, in the resurrection we won't have bodies that are copies or imitations of this present body, but rather our present bodies are in a sense a pale reflection of the resurrection body. We won't be less solid, but more solid. We will bear the same kind of bodily flesh that our Lord Jesus has even now, His eternal, incorruptible, immortal flesh. So it is written that at His appearing He will change our lowly bodies to be like His glorious body (Philippians 3:21), we shall be like Him. For having shared in a death like His, we shall also share in His resurrection. For the Spirit of Him who raised up Christ shall also raise us up and give life to our mortal bodies (Romans 8:11). Having borne the likeness of the first man (Adam) so shall we bear the image of the New Adam, Christ (1 Corinthians 15:49).
Most of what the resurrection is about remains unknown and unknowable; but that it is resurrection--bodily resurrection--is known because God has promised it and Christ has proved it. For He is the firstfruits, what happened with Jesus shall happen also with us. He was raised up, not invisibly or with a non-physical body, but in His own flesh, for He showed the wounds of His passion in His hands and side, and He showed His disciples His body saying, "See, it is I, Myself, a ghost does not have flesh and bones as you see I have." The same that happened to our Lord Jesus shall happen to us--that is the through-line of the entire New Testament when it speaks of our future hope: Resurrection, the dead shall rise.
-CryptoLutheran