You can choose not to feel offended. Your choice. I live opposite a church (second time in a row, actually) which also functions as a community centre. It's a nice Victorian building to look at and I do my bit to support it --because it offers an important function as a community centre. About the rest I'm easy as Sunday mornings. There are a lot of things in the world I could get more upset about. Poverty. War. Wanton violence and vandalism. As for people knocking on my door, I politely send them away. They politely thank me for my time and leave. It's all good. I recently attended the church wedding of my friends. It was their special day; they honoured me by inviting me to be part of it, and since this was about them, not me, I happily put up with the churchy bit (which was a spectacular 17th Century chapel, and the wise-cracking Vicar made it a really nice and upbeat ceremony). Didn't sing though --I don't know the tunes. Didn't join in the prayer, because I'm an atheist and pretending would be disrespectful. But I did respectful silence at those moments, not for God, but for the right of others to believe what they believe. My neighbours are seriously church-going Christians. They know we are atheists, but they invited my wife and me to their baptism anyway. We went and even joined in with the applause at the end of the ceremony. It doesn't mean anything to us, but we understood that it meant a whole lot to them and that they wanted to share that important moment with us, and we accepted that gift gratefully, even if it clashes with our living room decor (so to speak). But the buildings sure are pretty, no? No, sanctification is. By not joining your sister in her significant moment, you made your beliefs more sacred than your relationship with her. That is a form of religion, right there. Dude, it's ALL superficial crap. When was the last time you heard a politician sound profound, like? Religion makes no difference. People were good and bad before, and good and bad after. People are no better for it and no worse for it. You are barking up the wrong spire.