We know for sure Moses is not in heaven, as Jesus clearly said in John 3:13, “And no one has ascended into heaven, but he who descended from heaven, even the Son of Man.” No one who lived before Jesus was given the promise of a heavenly reward.  

When Adam lost the right to life in paradise because of disobedience, God told him (and by extension, all of mankind) he would return to the dust upon dying. “By the sweat of your face you shall eat bread, till you return to the ground, because from it you were taken: for you are dust, and to dust you shall return,” (Genesis 3:19).  Ecclesiastes further supports this eventuality for all living beings, “For the fate of the sons of men and the fate of beasts is the same. As one dies so dies the other; indeed, they all have the same breath and there is no advantage for man over beast, for all is vanity. All go to the same place. All came from the dust and all return to the dust,” (Ecclesiastes 3:19,20).

When he was nearing death, Moses was permitted to see the Promised Land from the top of Mount Nebo. But because he had failed to follow God’s directions faithfully, he was not allowed to go there. When Moses died, “the Lord buried him [likely by means of His angels] in the valley of the land of Moab, opposite Bethpeor; but no man knows his burial place to this day,” (Deuteronomy 34:6). His body has long deteriorated into dust. 

Yet he sleeps in God’s memory, as do all who die. We await the resurrection back to life in God’s kingdom, for which our Lord Jesus taught us to pray, “Thy kingdom come, Thy will be done on earth as it is in heaven,” (Matthew 6: 10). And just as Jesus resurrected Lazarus, who had already begun to decompose in the tomb having been buried three days, similarly will Jesus and his faithful followers in heaven resurrect Moses and all of mankind. This we are promised in John 5:28, 29, “Do not marvel at this; for an hour is coming, in which all who are in the tombs shall hear his voice, and shall come forth; those who did the good deeds to a resurrection of life, those who committed the evil deeds to a resurrection of judgment.”

Jude 1:9 adds the unusual detail of Michael the archangel disputing with Satan over Moses’ body, possibly to prevent idolatry among Israel. However, we know Moses truly died, consistent with the biblical teaching that death is the absence of life, trusting that God’s concealment of his body was for Israel’s ultimate good.