As far as why I choose to believe in the Christian God or the God of the Bible, is due to having witnessed, what many would consider coincidence but I would consider divine intervention. Yes, I can personally attest to prayers being answered just as asked.
So what about everyone else who doesn't get their prayer answered? Why are you so special? The Christian woman who got raped last week, and screamed out for God to save her? The 12 year old girl with the perverted stepdad that sneaks into her bedroom three times a week? The single mother who prays for enough food for her three children, but doesn't get an answer?
You were on the right road when you said coincidence. If God gets the credit for answering you, he also gets the blame for the other 98 percent of the time when he ignores prayers from people in worse circumstances.