Why don’t atheists believe in God?

Many people who claim to be atheists have problems with the world around them.  They have either been hurt by many Christians and therefore through those experiences refuse to recognize that God is there.  Or they may have had something traumatic happen to them or a loved one and they are angry with God and just decide it is better to believe that He is not there.  Still others have been talked into the idea that evolution is true and that they are the god of their own destiny.  There may be other reasons why someone would choose not to believe in God, but these are the most common answers that I have heard or seen.