Where did you read ashes being raised to flesh?
The human soul can burn and perish because God is a consuming fire. The fire holds 2 offices, it can warm and comfort us; and it can also burn and destroy us. Open the link for a better understanding on the biblical level.
The resurrection is about your soul being resurrected into a new body. It's a spiritual explanation of what happens when we die. Paul stated he doesn't want Christians ignorant to what happens when we die. The soul steps into a spiritual body....that simple.
God is A Consuming Fire
A Sermon by Dr. Neil Chadwick
The Bible speaks often about fire. For example, one Old Testament prophet used it as a symbol of God's cleansing power.
You see, even while we love to sing the songs about God's great love, we cannot avoid this other truth about God - He is a "Consuming Fire", and no matter how hard we try, we can't outrun God. But listen to the pleading of our Leader. He lays Himself down in the path of the fire, and all who follow Him shall be saved.
Malachi ends his book with another reference to fire; it's a stern warning and a wonderful promise, all in one passage.
"'Surely the day is coming; it will burn like a furnace. All the arrogant and every evildoer will be stubble, and that day that is coming will set them on fire,' says the LORD Almighty. 'Not a root or a branch will be left to them. But for you who revere my name, the sun of righteousness will rise with healing in its wings. And you will go out and leap like calves released from the stall.'" (Malachi 4:1,2)
http://joyfulministry.com/consume.htm