I think one of the best arguments against the existence of a personal god is the fact that suffering is so isolating.
God’s people dropping out of your life like flies. Me and many others on the bottom experience is that the people who claim to be closest to God are the ones that get the furthest away when things turn permanently worse. They do this all while parroting the romantic notion of suffering that things are going to go according to “God’s plan”. Well they’re not and you are part of the problem. Religious people will trot out their “free will” theodicy trump card when confronted with the problem of evil. But then they put it away when their free will is frustrating God’s supposed “perfect plan”.
The fact that for a lot of us suffering turns us into much less of an everyman than more of one. One of the things those of privilege selling suffering say is that it will somehow connect you to a greater experience of humanity. While that happens for some lucky people for most of us suffering cuts us off from enriching people and activities we need to actually become what they claim suffering will make us become. I have noticed in my life that I’m not even empathetic to people who have gone through the same things as me (mental illness). This surprised me. I’m just stretched so thin myself I have nothing to give. Plus there is this thing with mental illness called negative symptoms which actually eat your personality away which flies in the face of anything positive coming out of suffering.
The idea of drawing “meaning” out of suffering helps less people than you would think. Highly principled people may concoct backstories and astroturf the bad things in their life to things make sense in hindsight but that requires an expensive brain that can play good mental gymnastics. I want dignity and relationships, I don’t give a rip about meaning. Suffering actually robs my life of meaning because I found meaning in dignified work and relationships and what I suffer robs me of both.
Experiences of God going AWOL. The part of your brain synthesizing “experiences of God” is likely to go down if you suffer enough. Part of this is suffering and skills to cope with it make you emotionally numb and religion (or whatever they are calling Christianity these days) largely transpires on the seat of the emotion. Nobody wants to admit this but the way it’s sold (especially in contemporary worship) is all about emotions. Anything that makes you emotionally stunted is going to torpedo your interaction with “God”. This is partially why so many people on the spectrum are non religious because we don’t have the emotional toolbox to interact with a god.
The fact that a lot of us turn to the internet for refuge. When the world shuns you the internet raises you. Many forms of suffering like disability narrow people who will interact with you beyond reduced functionality mode to a subset of people which you find online. For example with me if someone doesn’t have a disability and/or mental illness the chance of a relationship happening is just about zero. Unfortunately for religion the internet is not a community friendly to religion partly because a lot of the people seeking refuge on it were already rejected by the church so they carry that with them. Also online interaction is not incarnational the same way real life interaction is so it’s less conducive to spreading religion.