I have objections to cremation theologically, but I am not very good at articulating theological arguments on subjects such as this. Having had this topic come up more than once I thought it good to find someone who has articulated my same thoughts on the subject. I found this to be a good argument: http://opc.org/qa.html?question_id=347
I particularly like how it points out that it’s not the problem that God can’t paste us back together at the resurrection because it is true that we all could be ashes before the Resurrection, but it’s the idea behind burning the body and the testimony that a burial gives to man that this isn’t it and this body will be brought back from the grave at the Resurrection. The number one argument is that it makes no sense to spend the money on a burial, but it’s not like it’s just out of the world costly and with insurance and even putting away just a small amount of money really in the end can you really say it’s a waste of money? Think of a burial as your last testimony to this world of the hope of the resurrection and the fact that death is the destiny of all people.