Does scripture support cremation?
Scripture neither directly supports nor condemns cremation. Orthodox and most Conservative Jews oppose cremation, but there is no clear scriptural basis for this. Many quote Genesis 3:19, which says, "for dust thou art, and unto dust shalt thou return." The argument is that we should allow the body to return to dust at its own rate. Additionally, it is a requirement in Judaism that there be a burial, based on several scriptures. One of them says, "And if a man have committed a sin worthy of death, and he be to be put to death, and thou hang him on a tree: His body shall not remain all night upon the tree, but thou shalt in any wise bury him that day; (for he that is hanged is accursed of God;) that thy land be not defiled, which the LORD thy God giveth thee for an inheritance." (Deuteronomy 21: 22-23) If this consideration is accorded a capital criminal it should be accorded to one to whom more respect is due. Of course, this doesn't say whether or not a body may be cremated before that burial.
The most common argument by the Jewish people, in fact, is that the body of the dead deserves respect. Burning, and even performing an autopsy, is violating the body in a way that would not be allowed in life, so why in death? Again, though, no clear scripture is attributed to this belief.
There are only possibly two passages in the Bible that address the burning of a dead body. In Joshua 7:15-25 Achan had taken things from the destruction of Jericho that had been forbidden. When it was discovered, he and his family were stoned and then burned. It is not clear whether the burning was while they were still alive, although it appears that they were dead by that time. The other instance is in 1 Samuel 31:11-13. King Saul committed suicide on the battlefield. His body and his sons' bodies were hung on a city wall. After several days the men of Jabeshgilead came and retrieved the bodies. They burned the flesh off the bones, then buried the bones. There is a translation that uses the word "anointed" instead of "burned." Both words are apparently similar in Hebrew. Thus it may be that Saul was not cremated. Even if he was, both instances are of criminals (a thief and a suicide) being burned.
These passages can not be used to justify or condemn the practice of cremation. You won't find any passages that clearly do either. Most Christians and many Jews allow cremation. For most it is a matter for personal choice rather than direction by scripture.