The reason why I'm an atheist isn't the same as the rationale for being atheist. I was raised one. Neither of my parents believed, so I didn't either. It wasn't as though I haven't been exposed to religious salesmanship my entire life.
This fell into two questions: "Who made everything then?" That was quite an easy one as I liked astronomy and dinosaurs. Genesis just wasn't true.
And Jesus. Too much of the story was fantasy. The nativity especially, the walking on the water, the resurrection. It was a harder one as these were supposed to be eyewitness accounts. But there are quite a lot of claims and stories, not only in other religions but in the Occult and Flying saucers. Witnesses may not always agree, but witness can also tell tall stories.
In my teens, after I had spent some time in a church choir (and had not been impressed by the religion) I considered the questions seriously. "Who made everything, then" Had to answer 'Which god?" and I postulated an "agnostic -god" of all religions or none. The "God" of Einstein; the Mind that runs the universe, or at least, started it. I was Ok with that, and still am.
On the religion front, US evangelism had their chance. Like all the teens in the 60's I listened to pop music (1)and the only place to hear it was from Luxembourg. Yep, if you can believe it, Radio and TV had banned it. "BCM Ambassador" advertised on Radio Luxembourg with promises and threats about the Last days Armageddon and proofs of Prophecy (Tyre was particularly mentioned) and claims about Soviet Citizens secretly tuning in to hear "The Good News about the World Tomorrow". I sent for their stuff and said to myself, "We'll see". The predicted date (before 1970 - I still have their literature, somewhere) came and went, and so did they, confining themselves to peddling copies of what I call "Plain Lies" magazine. That was the end of the line for US evangelism for me. (2)
I was now deep in archaeology and when not digging up Belgic pottery, read about the cultures and religions of Egypt and Sumer and all the various beliefs. That not only made me realize just how many religions there had been but it also enabled me to handle the Gods from outer space craze that Dainiken set off and gave science a bad scare (3).
Two things started me travelling: I was tickled pink to find that, although the ancient cultures of Assyria and Rome were now at best ancient monuments, in the east, they still seemed to be alive.
And the question of a sortagod. While not being the god of any particular religion, wouldn't it want to get in touch with us? What was the way to do it? Prayer was the evident way, but not the "Please God, let my Boss die so I can get his Job" type of prayer, but a mental method of contact. I looked at Sufism and it was very much what I was looking for, but I couldn't take the Islamic trappings. Buddhism was close to that and it was even a backdoor into Hinduism without needing to worry about their odd gods.
So I gave Buddhism a go, even became a monk, mainly to please my Burmese wife. And in the course of that exciting mix of Burmese antiquity and a Burmese romance, l experienced two miracles: spontaneous healing and an answered prayer. Except it was a wrecked back that miraculously healed just as the doctor called
and my job relocating to Wales enabling me to sell my mouldy London flat for enough to buy a 4 bedroom house here - just when I needed to have a house to enable Mrs Arq to get a UK residency visa. Of course, I wasn't praying either time, never mind to Biblegod, but it was a lesson of how coincidences can be made to look like evidence of answered prayer and miracles.
The final bit of the puzzle was when a Christian work colleague urged me to really read the Bible -especially the Jesus -story. So I did. I began by trying to sort out the contradictions: see what of the four accounts worked together, understandable slips aside and what can be regarded as really additions that can be set aside without affecting the validity of the whole (4). I took my findings back to him and first came across Atheist Axiom No 1: "Religion makes an honest person dishonest".
Peter was the nicest, most decent person I know (still a mate of mine) but the evasions, excuses and refusal to look at what was evident fact was a revelation. Finally he said I have to look at the "Big Picture".
"This IS the Big Picture."
I found out that what he meant was 'Never mind the evidence (5) Just have Faith".
That explained everything about religion just as my study had revealed the Truth about the Gospels. That added a whole new discipline to my disbelief and to my life. It sent me to the religion discussion online, and to logical reasoning. It led me to another discovery - that the UFO world was also based on Faith -thinking and uses the same methods.
So here I am, still atheist, and more firmly so than I ever was. The rationale - and sound it is - came later and mainly through questioning. But the reason I am atheist is that I was born and raised that way. That's why you need two things: a society that doesn't force religion on you in the home. And the evidence and rationale easily available when they try to force it on you outside the home. That is why I am a militant atheist and why calls for us to shut up and go away, go into the same bin as all the other religious and cultish garbage. I have seen it all before and you can't fool me.
(1) Though at school, we had been introduced to classical and "The Planets" had blown me away, I would not be hooked until (at age 17) I bought the first solid state stereo (still got it - and my valve radio, both still work) and the demo. record of the finale of Tchaikovsky's 4th made me realize what I had been missing.
(2) I'd also been looking at the claims of Prediction and took "Fate" magazine for a while. Some simple tests showed that it didn't work and there was a lot of frankly money -making swindling going on. That went in the same Bin as Revelation.
(3) in my 20's, I had met my best mate and he was into UFO's and he got me interested. At one time I was half convinced, though both he and I were aware of a LOT of tall tales and bullcrap in that area.
(4) The shekel -eating fish (Matth 17 24-27) is surely the touchstone example.
(5) only when you find out it doesn't support what you want to believe.