Living in fear of not 'being good enough' to gain access into heaven .... centering your life around "sucking up" to an invisible entity by following rule books handwritten by man... obsessing over silly ideas of 'life after death'... ideas that have no legitimate backing....

Life as a religious beliefer is silly, miserable, and wasteful (of your time here on earth).

Why do atheist feel the need to spread their knowledge? That's simple... it's because of the ill effects of religion and the role it plays on a person's behavior & psyche. Educating yourself and gaining the ability to think logically (taking that brave step outside of your 'religious self') is necessary to attain personal/psychological freedom.

For an Atheist... our humanism & the freedom which follows, after adopting a secular thought system, brings our happiness. Education and our innate ability to perform good is what creates a quality lifestyle for us. We (atheists) live within the realms of reality (the NOW). Our 'heaven' is here on earth and it's our responsibility to make our experiences as positive as they could potentially be. People place too much faith in god, and not enough on themselves.