Well let's look at "God's" track record:
1. He created the first man and woman; they ate an apple, He kicked them out of paradise and forced them to endure labor and work for the rest of eternity.
2. He thought people (who He made in His OWN image) were vile sinful assholes, so He drowned them all, with the exception of one guy and his family who were responsible for saving all the creatures of the world, which were NOT made in His image, yet which HE liked better than humans.
3. He smote all the first born children of Egypt. (Do I have that right?) Then sent His "chosen" people, the people he liked most, to wander the desert for 40 years, and be shit on by the rest of humanity for the next several thousand years.
4. He sent His only begotten son to Earth to spread His word and JUST when people were starting to listen, He killed His son using the most torturous execution method yet devised by man.
5. He "designed" us to have certain overwhelming urges and inclinations ALL of which in direct violation of the rules He set up for us. If we lead the most bland, un-exciting life imaginable, our "reward" is eternity basking in His radiant awesomeness... If not, we roast in an eternal pit of fire.
So yeah, if He does exist, this guy's a raging fucking asshole. The LAST thing we ought to do is be as "merciful" as He is.