When we die we either die in Christ, and then there is a cross on our grave, or we die and go to hell, where the fire never stops.
What desire, do you think, does a flame emerging from the grave express?
I might suggest you actually do a little research on what the eternal flame expresses...
There is one in the tomb of the unknown soldier in the Arc de Triomphe in France...
You actually think these nameless soldiers are damned to hell because of a flame on top of their grave...?
You actually think having a cross on your gravestone is indicative of your final place...