I do wish you would think before you write.
This void you theists keep talking about does not exist.
There are people who believe as you (when you're not lying) and people who do not. There is no void.
People who do not believe are not going to be converted to islam, are they? It is people who do believe who may be converted so if islam takes over then it will be because lots of people believe the fairy stories.
So, you see it is people believing which may lead to what you fear.
It would be difficult for islam to take hold if 100% of the population were atheist.
This is the problem , Roger the liar and BnB simply can't think. They can't even understand what they are arguing for or against.