And God ordered the extermination of the Canaanites, the Amorites, the Hittites, the Perizzites, the Hivites, and the Jebusites -- which was actually the SECOND big extermination.
The first big extermination was when God supposedly caused a flood which rose to a height of 29,135 feet to exterminate every living thing on earth except for Noah, his family, and the Ark.
The Flood, however, is physically impossible: for the atmosphere to contain that amount of precipitable water, the atmospheric pressure would increase to over 13,000 pounds per square inch -- effectively crushing every living thing on the planet.
Moreover, using the "canopy" model described in Genesis, if a canopy holding the equivalent of more than 40 feet of water were part of the atmosphere (and the water allegedly rose to a height of 29,135 feet above mean sea level), it would raise the atmospheric pressure accordingly, raising oxygen and nitrogen levels to toxic levels.
• If the canopy began as vapor, any water from it would be superheated from the intense atmospheric pressure. This scenario essentially starts with most of the Flood waters boiled off. Noah and company would be poached. If the water began as ice in orbit, the gravitational potential energy would likewise raise the temperature past boiling.
• A canopy of any significant thickness would have blocked a great deal of light, lowering the temperature of the earth greatly before the Flood.
• Any water above the ozone layer would not be shielded from ultraviolet light, and the light would break apart the water molecules.
Assuming that the atmosphere had enough precipitable water to cause a flood which rose to the depth of 29,135 AND that all of life hadn't been crushed because of the intense atmospheric pressure AND that nitrogen and oxygen levels hadn't risen to toxic levels before the flood -- for the water to rise 29,135 feet in 40 days, rainfall across the entire planet would be on the order of six inches *per minute*, or 30 feet of rain *per hour* and the force of that much rainfall would have destroyed any dwelling or any boat it hit.
Moreover, had the water somehow reached the height of 29,135 feet, adabiatic cooling would have taken place which would have resulted in the top two miles (or so) of water becoming ice.
And by the way -- I'm Christian. I just don't happen to believe the Genesis stories were ever intended to be read literally; and when they ARE read literally, the stories become absurd (and we miss the complete point of the story).