As the Egyptians believed in many Gods until one man decided the Sun gave life so everyone then had to believe in that, he was then declared a heretic & everyone went back to believing in the many Gods again, man made! My point being we have to believe in something many ideas have been put forward all by man, if you are a believer then that is fine but if you are not then that is also fine. But as many have said there is no concrete proof that one God exists only what has been said by man.
If there is only one God , why do we fight to say that each different faith is the right one to worship him ?