1. Why atheists spend so much time coming up with ideas to disprove the existence of God? That actually transform them into negative believers. If God exists or not there is no need for believers or anti-believers, we don't matter.
Atheists are negative believers, it's the very definition of atheism: one which rejects the existence of a higher power, deity, God, etc... were you thinking of agnosticism? There is an important difference. So obviously atheists are going to come up with ideas to disprove the existence of God for the exact same reasons that believers are going to come up with ideas to prove the existence of God, in endless debates and heated discussions, yet never truly reaching one another.