What idea solidified that god doesn’t exist for you? Was it historical? Scientific? Philosophical?

Disclaimer: I am a deconstructing theist and borderline atheist. Quickly moving away from religion. I am not here to “gotcha” moment anyone. I am genuinely interested in these opinions and want to see them to incorporate and expand upon my own ideas to help me deconstruct. My past few post have been from a “theist” perspective and I am trying to refute the Christian stance. I would definitely enjoy any responses to those posts as well.

I am very interested in the ideas that lead people to leave a religion, renounce god, or if you never had faith what is the most absurd idea you have seen used to justify religion and how would you refute that position.

Lastly on a more fun and constructive note if theists were looking for material to study and read to help them deconstruct what would you recommend for them? Is there a book of line of study personal to your own ideology that would help a theist get over the last hump of deconstruction?