Not sure if this is what you're getting at or not, EWQ, but it... depends on what one means when the speak of the fire and water, which on its face I'm sure seems like a ridiculous thing to say to some folks here, but...Jesus also mentioned the flood of water also. In no way is he saying water or fire will be used to kill when he returns.
The flood in Noah's day that swept away every living thing besides Noah and his family and the animals in the Ark and the fire from heaven that destroyed Sodom and Gomorrah and all those who dwelled therein were pictures... images... of the real reality, so to speak, that will ultimately be at the end. God will ultimately and finally cleanse all creation of sin and death, and refine... in the sense of renewing, making completely new again, all creation. That seems to be what you're getting at with this.
You're right:
- God promised in Genesis 9:11 to "never again ...cut off... all flesh by the waters of the flood, and never again... would there be a flood to destroy the earth."
- And... our God is a consuming fire (Hebrews 10:29), which of course is not a statement concerning the physical make-up of God but... well, His character, to put it succinctly.
Grace and peace to all.