Can God resurrect a body that has been cremated or burned at the stake?
Yes. Death, cremation, or being burned at the stake cannot stop God from resurrecting. He knows where the smallest particles of the original body are, and He will take at least some original cells and reconstruct a new resurrected body. Scripture does not forbid or encourage cremation.
Les teaches that 1 Corinthians 15 is a total chapter dealing with resurrection. He explains that men die and can revert back to dust, be cremated, or be burned at the stake, but that still will not stop God from actually bringing the smallest particles of that original body. They are still someplace, and He knows where they are. He will take at least some of those original cells and reconstruct a new resurrected body. Les also answers the common question about cremation by saying he does not see that Scripture forbids it or encourages it. Personally, it is anathema to him because he feels that cremating a body tells God to try and bring that back to life, though that may not always be the mindset. He is not in favor of a definite cremation. He notes that during the Reformation, many of God's choice servants were burned at the stake for their faith.
Moreover, brethren, I declare unto you the gospel which I preached unto you, which also ye have received, and wherein ye stand;