I’ve studied Aquinas, Augustine, and a few other philosophers who did God some justice including Descartes (though his argument is worthless compared to others).
I do not know enough of the Big Bang theory to accept or condemn it, so for now, I must rely on my study of philosophy.
Rationally, I can see why one would believe there is a God. I admit, even in this bout of atheism, that there may be a God, but I have chosen to live my life based on the assumption that there is none.
However, my problem is not with the existence of God, or the infinite creator. My problem , and what has led me to atheism, is doctrine - the idea of Jesus as the savior, the concept of “sin” even existing, or there being a God that not only created the universe, but oversees it today, judging our sins and dividing humans based on how faithful they were as mortal beings.
Due to the combination of the lack of scientific progress and the the increased rate of gullibility of the population in metaphysical philosophy that would inevitably be a product of a non-scientific environment, it seems irrational to believe in an ancient text rather than contemporary advances in science.
I am aware that faith is only faith because we can’t reason our way to conclude that, for instance, the blessed sacraments are actually the body and blood of Jesus during every Mass. Such things are only derived from the Bible, which Catholics must accept wholeheartedly.
However, I am fixed into the atheist mentality and, at least for me, it would be extremely difficult to return without disregarding my new intellectual standards of proof and rationality being present in my commitments. Thus, I figure that I would have a better chance addressing intelligent people rather than my friends.
I am very unwilling to chalk this up to being a “phase”, for most events that have been known break such a “phase” have already happened in my life. I am, of course, talking about near-death experiences, familial deaths, and other events that have made me want to believe that this life is not all we have.