I assume, since it is okay to share one's personal journey from faith to atheism, that it's okay to describe the reverse?
I was an atheist at one point in my life. I had reached a point where I completely rejected religion, mysticism and spirituality based on the fact that there was no factual evidence to support the claims made. Not once did I see any concrete evidence to support the beliefs of the followers of these creeds. And it made no sense to follow any of these belief systems- they were fatally flawed because they made incredible assertions without any evidence at all to support those assertions. To my mind, that was that.
I think the fatal flaw in my reliance upon rationality lies in one simple fact: I am human. Being a human I am somewhat irrational to begin with; I don't start life approaching problems or situations rationally - I have to be trained into doing so. If science came to us naturally, instinctively, we would be a vastly different animal.
In my case two irrational factors (both with likely biochemical basis) conspired to shatter my world: unipolar depression and alcoholism.
Without going into gory details I'll simply relate that the alcoholism had me to a point where I was drinking between a pint and a quart of vodka each day. I reached a point where I literally did not want to drink, I hated drinking, hated how I felt and I still had to drink. The depression provided a solution to this situation: suicide.
Up to this point everything I describe can be explained by biochemistry. The dependance my body had developed on alcohol; the failure of my brain to produce the correct amounts of dopamine, serotonin, and norepinephrine to maintain a balanced mood. The alcohol, being a depressant, would also have affected my brain chemistry. Throw in a malfunctioning thyroid gland which required supplementation and you really had a recipe for disastrous depression.
Even in the condition I was in, I was aware there was a rational explanation for everything.
In the extremity of need I asked for help and the craving for alcohol was gone. I feel somewhat embarrassed even telling this story because I can and have heard all the objections: there's another biochemical explanation, this is an anecdote, a testimonial and has no value as evidence, you're mentally ill and your brain cannot be relied on to give accurate information, etc.
From my perspective this is nothing less than miraculous. And I guess you have to actually be in my shoes to understand that. Ten years ago, stealing money to buy booze. Now, never even crosses my mind. The urge is gone.
G*d, or whatever, did not fix my life. I still fight hellacious depression and suicidal urges at times. I have to take my meds, go to my psychiatrist, excercise, eat right to have a balanced mood.
But I also have periodic, weird, inexplicable things happen which help me out just when I need it. Green lights through 30+ lights on my way to the hospital to meet my wife who was in labor. Inspiration often comes to me out of the blue. It's hard to explain, and I'm sure there are those who can dismiss it all, but I don't anymore.
I see miracles everyday. Like the sun rising. Or my daughter laughing. Ordinary but miraculous all the same.
Science is still central to my worldview. It's just that it is not my only way to view the world anymore.