The question/comment about prayer...
I'm coming from a Roman Catholic perspective, so I'm not going to be able to speak for the new non-denominational, evangelical beliefs...
We were taught that prayer is for worship/meditation and asking God to help us help ourselves... You can't ask for God to help you with a math test, or to help you win the lottery... Our swim team had sweatshirts with "God is on our side" printed on the back, not as an actual statement, but as a tease to the teams they were swimming against, knowing full well that God was not going to favor the Catholic team over those from the public schools.
I believe that prayer is not a way to ask God for anything other than help to realize my own potential... "Help me find the strength," not "Give me bigger muscles."...
Putting our faith in God through prayer gives us peace of mind during stressful or crisis situations, just as those who practice other forms of meditation find peace doing what they do (which I also do, by the way)... It's a way to just calm down and take stock, knowing that while God may not swing down and keep the crisis from happening, our belief that there is a God and Heaven gives us some solice and peace, should the worst happen. Atheists cannot proved God doesn't exist any more than the faithful can prove he/she/it does, so why not trust in your faith.
Full disclosure that I am also a kind of deist, in that I believe that God does not intervene with daily life.. He set out life in the Universe and lets it take its course, with occasional adjustments along the way (see also: Jesus)...
And to answer the question as to why some religeous faithful don't just leave the atheists alone, the answer is simple... Teachings in almost all faiths dictate that it is the duty of the faithful to preach the word and convert those they meet.. It's not because they are jerks, it's because that is their belief.. Personally, I have a distaste for that kind of thing.. I like to be left alone as much as anyone else.. But if someone asks me about my beliefs, I'm glad to tell them...
They usually end up more confused than before they asked..