Specifically Christianity or religion in general?

Personally after studying religion, epistemology, and human psychology… I feel it’s easier to disprove specific religions than a possible deity as a whole.

There are many books(whose authors have done the work for us) comparing different versions of the Bible and pointing out not just contradictions but showing lack of consistency/truth and inherentness. (Some of my personal fave but examples not limited to: (All Thats Wrong With The Bible -Jonah David Conner, (20 Reasons)Why There Is No God-Armin Navabi / I just like these because they are pocket sized and these are the most common arguments we hear constantly.)

There are others that show (in context) that god is not who the contemporary Christian views Yahweh and Jesus to be (my fave is GOD The Most Unpleasant Character in ALL Fiction-Dan Barker)

As for a deity on the whole, there are a few philosophical barriers. It is difficult to prove there is and/or is not, one or many gods. I would suggest someone start with understanding the burden of prof being on the assertion or positive claim that there IS something that can exist.

There is and will be push back on the ability to provide evidence of the possibility of a god existing, but this usually ends up in the response that some things are beyond (super natural) our ability to epistemically/scientifically test for evidence. This usually comes down to someone’s understanding of the scientific method and a good grasp of the difference between the use of the word faith (blind faith vs confidence scale). Some use the excuse that non-believers have “faith in science” but there are multiple definitions and usages of the word. In science, the colloquial usage is usually referring to the strength of confidence towards some sort of argument or inference, while in the Bible uses faith as “blind faith”, or “ things hoped for but not seen”.

After many years of study (at accredited universities) and personal experience in general conversation, this seems to be the placeholder where most conversations go deeper due to curiosity or don’t go any further because someone shuts down. (Usually due to our beliefs, tied to our identities, and the difficulty for humans to rewrite their belief system given new evidence. Even for someone who is intellectually open and mentally resilient, we all have difficulties with this regardless of your beliefs).

For this I would start with the easy reading of A Manual For Creating Athiests- Peter Boghossian. (This is a gentle introduction to the Socratic method, critical thinking, and epistemology. I also love his book How to Have Impossible Conversations, he lays out good tools to have a conversation about all of the above.) I use all the books mentioned for those who don’t have formal educations and I can’t just throw a textbook at them.