I am an atheist. This is because I am an empiricist and see no evidence for god’s existence or the possibility of his existence. I am, however, faced with Pascal’s Wager: If god is real, I can either believe in him and go to heaven, or not believe in him or go to hell. If he is not real, I can either believe in him or not believe in him and the outcome after my death will be the same. From this standpoint, it makes sense to be religious, as it incurs no risk of hell if god were to be real.
My justification to myself for risking that by being an atheist is that I don’t believe a benevolent god would make it a matter of faith to believe in him. In other words, I don’t believe that a benevolent god would damn me to an eternity of the most horrific suffering imaginable simply for coming to a rational conclusion based on observation of the world he created using the senses he gave me. If a god would do that, I don’t think he is benevolent, and it is another question as to whether or not I would like to dedicate my life in service to him in order to live in his presence for eternity.
Keep in mind, though, I have never read the Bible. This is the argument of someone with a normie’s understanding of god, and maybe once I get around to reading the Bible I will be presented with a different set of circumstances under which my argument would not stand. Until then, this is how I philosophically justify my atheism.