How can you be sure that God doesn't exist?

[downbeatplumb]

Hi,
 
 I am a new member here.
 I made this account, largely for one simple purpose, which was to find out why you believe in what you believe.
 It is not so much a quest to change you or 'convert' you, but rather to find out your beliefs and motivations. I just want to know the background you are coming  from ...

 As for my own identity, I am of Jewish faith, and was an ex-atheist ... So, you can get an idea about my own background.

 Why do you believe that God doesn't exist?
 How can you be sure that God's existence is not real, for certain?
 Humanity has still not uncovered a great deal about our own existence, or what's on the other side of the universe.
 
 If anything, one can only be agnostic, rather than an atheist.
 The logic I am going by is that atheism states that only hard evidence should be used to prove or disprove something; that is after all, the scientific way. Given that there is no evidence to prove or disprove God, you can only be agnostic rather than an atheist.
 For those who don't know what an agnostic is, agnostics are neutral towards the idea; they don't know if God exists or doesn't, and so are open to both possibilites, but conclude that at a human level, is impossible to know the truth.
 
 So anyway, I would like to know why you believe that God doesn't exist?

 
 
 Thank you ...
 Sincerely,
 
 - RandomGuy123

I was born into the UK which is largely religion free.
Never believed in god, have seen nothing that would make me start.

I have never even seen a very good description of what a god could even be all the descriptions are nebulous.