"And when the inhabitants of Jabeshgilead heard of that which the Philistines had done to Saul; all the valiant men arose, and went all night, and took the body of Saul and the bodies of his sons from the wall of Bethshan, and came to Jabesh, and burnt them there. And they took their bones, and buried them under a tree at Jabesh, and fasted seven days" (1 Sam. 31:8-13).
The other reference to the burning of a person's body, does not tell us whether or not the person has died first. It may refer to sacrificing oneself by being burned alive. Regardless, the outcome is the same, as the body of the deceased is consumed by fire. This passage is found in the New Testament, and it speaks of the importance of one's motive when he or she gives permission to have his or her body burned. The Apostle Paul wrote:
"Though I speak with the tongues of men and of angels, and have not charity, I am become as sounding brass, or a tinkling cymbal. And though I have the gift of prophecy, and understand all mysteries, and all knowledge; and though I have all faith, so that I could remove mountains, and have not charity, I am nothing. And though I bestow all my goods to feed the poor, and though I give my body to be burned, and have not charity, it profiteth me nothing" (1 Cor. 13:1-3).
Note that Paul is comparing positive things: speaking in the tongues of angels; prophesying and having understanding, knowledge, and faith; giving all of one's possessions for the poor; and giving one's body to be burned. It is very unlikely that Paul would have included one offering his or her body to be burned, in this context, were it a negative thing to do.
Let the record show that my cremation is motivated by love for my wife!