Atheist Apologism?

I go to church every Sunday.

I'm sure a lot of you do, too, but the major difference there is that I am an atheist.

Let me explain. I was brought up in a Lutheran church, and for the majority of my life, I really strongly believed in its teachings. It took many years of soul- and philosophy-searching before I came to my own personal conclusions that, while I can never prove for certain that there is no God, I seriously doubt that he exists and my life will be best lived under the assumption that he doesn't. I continue to respect others' religious beliefs and do not force mine on anyone unwilling to hear them.

I have a job at the church in which I was brought up; I've worked there for about three years, running the children's nursery during services. I love that job absolutely to pieces. I am nuts about all the kids who come play, and they adore me too. I'm polite, responsible, respectful, prompt, and energetic. Parents tell me their kids ask all week when they get to come back to see me! It's incredibly rewarding. Many babysitting clients, employers, and friends have emerged from this experience.

My dilemma is, of course, that I am completely silent about my religious beliefs to all these people, to the point of being almost embarrassed and apologetic. Even when topics like religion and God come up, I sort of squeamishly avoid any personal comments. It’s not just at church that I feel awkward -- my boyfriend’s parents, who are practically family already, have no idea of how unreligious I really am.

I just can’t help feeling like I will lose their respect, insult them, or in some vague way make them uncomfortable.

What is this phenomenon of atheist apologism? 

I’m interested to know reader feedback about religious discussion. If you are religious, how do you feel when you find out someone you know is atheist? Do you see that person in a different light, do you feel like you ought to try to help them change, is it completely irrelevant to you? If you are not religious or of a small religious minority in the West (not one of the Big Three monotheistic faiths), how do you deal with situations like mine?

I’m always eager to talk to people of every background and ideology!