As a witch, I can confidently declare that there is only One True God and killing it or otherwise besting it is a laughable and infantile idea that only reflects the depths of one's ignorance.
There are also self-proclaimed Pagan Gods, as well as Demons and other geists (lines get blurry between them all tbh) and while it is technically possible to kill them, or rather "kill" them because non-biological beings don't live in the same limited way you mortal live in, so you can "kill" them (by, for example, resisting a temptation or mastering one's feelings, thus killing the Demons residing in your head), it is about the same as fighting with wind mills.
As a witch, I have reliable ways of dealing with them in more productive fashions. Ranging from minor inconsequential and transient Demons like those that plague an individual and lead him astray from the path of righteosness to actually important Demons and Devils like Astaroth, the local deputy Mayor of Hell or even Satan himself, I can find a deal that pleases both me and them while technically not being blasphemous enough to make the big G displeased.
Navigating a deal that will certaintly not damn your soul for all eternity against an arch-master of deception and sophistry is far more interesting that... just brawling. And a lot less pointless.
TLDR: Killing gods is stupid when you can trade with them. Let's have some class, we are not stupid barbarians after all. Make love not war.