I believe I can definitely understand and agree with you.
I find random interjections of religion, and not just from Christians, to be distracting, taking away from the natural flow of conversation, and I get the distinct feeling people who do this are either weak in their beliefs and have to keep reaffirming them out loud to prove something, or else they are phony and trying to look good, or else they really do have such a one-tracked mind.
I don't appreciate all the public "I will pray for you" emails that get sent on mailing lists in reply to soneone posting a message that causes concern. Why not just send those prayer whishes to the person privately so as not to clutter up the listserv and archives? Same goes for birthday emails on mailing lists. *Cringe*
But I find people who continue to insert religion into every conversation to be irritating. If you're just talking about something completely unrelated, and then someone suddenly sticks in a scripture at random or says "Yes, God is amazing" or something like that. Or even "We must pray for that person" Argh.
A few people are hostile toward you and Christianity in general, but it also looks like you have a lot of much better answers from people who really are understanding. I rated all the good answers up and the others down.
I'm here to let you know that you're not alone. I am also a Christian, and what you are talking about here is one reason I don't frequent Christian communities on the net. I'm a very private person when it comes to prayer, I don't memorize anything written very well, so, don't just quote scripture at people, and feel rather put off by people who do when the context isn't right - I.E. when the conversation had nothing to do with religion.
Also, I stopped writing fiction with a religious person, because she was sticking her religion into the story just too much, so that it seemed as if it was turning into a piece of fiction designed to promote her beliefs rather than anything. - And she was a neopagan.
So, it isn't just Christians who go overboard with religion.
Anti-theists are the worst.