"This is a weapon. A weapon used to kill God!" -King Charles Lee Britannia
A weapon used to kill God... A very powerful statement. I have no ambitions of doing so, and I don't personally think it can be done. Not with a weapon at least. But what if you killed every Muslim and destroyed all their sacred text and any evidence that they ever existed? Everything! Would that kill Allah? Or what if you did the same to Christians? Would that kill God? Or what about the Hindus and all their Gods? Erasing them, would it kill their Gods? Would it even be possible to exterminate such a thing, a people and all evidence? Or would the true God stop such a thing from getting to that point? Or would he let his people die and start anew?
I am Christian myself. I don't believe Allah or any of the Hindu gods exist. However, for the sake of this idea it's interesting to play with them in such a way.
God was here before all of this. So even if you leveled the world with nukes, destroying all human and animal life alike, God would still exist and live on. If he could live before us, he could live without us. Yes, I imagine he would be heartbroken. All of his children, all of the people he loved would be dead... With that in mind, I don't think he would allow us to nuke the whole world. But even destroying all of us couldn't kill God.
So truly, as powerful as "a weapon to kill God" sounds, it's a false statement. There is nothing that could kill our God. Nothing powerful enough to harm him. Nothing he would allow us to do to each other would harm him. He is God, the immortal caretaker of us all. I can't dream of why you'd want to kill someone as magnificent and loving as him, and I can't imagine you could even if you wanted to.