Atheists, tell me, a Roman Catholic: why should I become an atheist?

[Mister Agenda]

Why should you reject catholic theology? Because, when looked at objectively and dispassionately, you'll realise that the god you've been taught to believe in is both logically and physically impossible.

Not alone does your got not exist, there is no possibility of him existing.

I'm commenting to Belaco but jumping off Tazzycorn's comment. Tazzycorn may be a gnostic/strong atheist, but all we know from the statement is that it's gnostic/strong atheism in regard to a particular version of God. Being sure Vishnu isn't real isn't the same as being sure that, say, the deist version of God isn't real.

I'm a gnostic atheist towards the God described in the Bible, taken literally. There's no God that flooded the earth or made the sun stand still in the sky or made the universe and the earth in six literal days; because those things didn't happen. I also don't believe in the God of theodicy because it has contradictory attributes (an omnipotent God can do anything, and omniscient God can only do what it has foreseen it will do). The deist God and Vishnu and Artemis don't contain necessary contradictions, so I can't say they're impossible; just that there's very little good reason to think any of them are real; so I'm an agnostic atheist towards them.