As a 'rather sane' person i can confirm God is personal and interacts with people, think as you wish, but here is my testimony that i and others have experienced things with God and have the absolute certainty he is up there. If what a person experienced is not enough to even you consider what we have to say and you require 'scientific proof' then you won't find enough proof or God.
Also 'former theists' don't exist as 'former christians' because when you meet the holy spirit and God, there is no one that can tell you not even yourself that God doesn't exists, and after having that kind of encounter with God you would need to betray him totally to become a 'former christian' and that doesn't appeal to much people, because after meeting God people get convinced enough about God and that is totally worth it to try to get along and have a good relationship with him, having God is so much better, and nobody who knows the holy spirit would want to just separate themselves from him, and reject God altogheter. This is the craziest and unthinkable thing a person would do after knowing the truth and God.