E D I T
Before we attach 'affixes' to a real word, we have to recognize its root; and in this case, it is 'theism.' So, the root of theism is the Greek word theos, or "god."
Atheists, you can yell at the top of your lungs... But, the fact remains that you've been shot in the torso, once again! I could apply more pressure... but, let's just take it one step at a time.