I see the body of Moses as the body of work God accomplished through him. The law and the prophets. That, I believe, is the body the devil disputed about...the body the devil wants to destroy.
Jude 1:9 Yet Michael the archangel, when contending with the devil he disputed about the body of Moses, durst not bring against him a railing accusation, but said, The Lord rebuke thee.
As Moses said, "all the words of this law"..."it is your life." It was his life, his body and the devil hates it.
Deuteronomy 32:45-47 And Moses made an end of speaking all these words to all Israel: And he said unto them, Set your hearts unto all the words which I testify among you this day, which ye shall command your children to observe to do, all the words of this law. For it is not a vain thing for you; because it is your life: and through this thing ye shall prolong your days in the land, whither ye go over Jordan to possess it.
2.Where are the bodies of those who died before the cross?
All flesh returns to dust and remains dust. The souls of those who died before the cross remained in their
spiritual graves until Jesus was resurrected. Then:
Matthew 27:51-53 And, behold, the veil of the temple was rent in twain from the top to the bottom; and the earth did quake, and the rocks rent; And the graves were opened; and many bodies of the saints which slept arose, And came out of the graves after His resurrection, and went into the holy city, and appeared unto many.
The "holy city" wasn't the earthly Jerusalem where Christ had just suffered. Literal flesh bodies didn't walk the city like zombies. It is all spiritual.
3.Where are the bodies of those who died after the cross?
All flesh bodies remain dust...forever! There are however.....
1 Corinthians 15:40 There are also celestial bodies, and bodies terrestrial: but the glory of the celestial is one, and the glory of the terrestrial is another.
Our terrestrial bodies remain while our celestial bodies return to God...
Ecclesiastes 12:6-7 Or ever the silver cord be loosed, or the golden bowl be broken, or the pitcher be broken at the fountain, or the wheel broken at the cistern. Then shall the dust return to the earth as it was: and the spirit shall return unto God who gave it.
Our celestial bodies are either spiritually alive or spiritually dead but all are with God.
4. Who will resurrect at the last day?
There are two resurrections. The first is one that is accomplished while we are physically alive...or it would be too late to be of the first resurrection. The other happens at the end of the millennium when God finds those in the book or cast into the fire.
Revelation 20:15 And whosoever was not found written in the book of life was cast into the lake of fire.
In whom does He walk and abide? For there is heaven.
2 Corinthians 6:16 And what agreement hath the temple of God with idols? for ye are the temple of the living God; as God hath said, I will dwell in them, and walk in them; and I will be their God, and they shall be My people.