I am an atheist, but i'm very happy that people are happy with their religion. That's awesome! If they say something towards me that involves their religion, I'm okay with it as long as they don't try to actually get me to convert to their ways. But I take every greeting as a sign or respect, regardless of the religion that it comes from.
I don't know why anyone would be offended by it. With some people it isn't even attached to religion. Whether it is or isn't, you have someone sending friendly positive thoughts your way. Why would anyone object to that? I like friendly positive thoughts directed toward me, they make me think friendly positive thoughts in return.
Not being able to say your own religion is taking away your own rights. Everyone should be fair to one another, we shouldn't have to feel like our religions are something to hid from other people, we all have something we believe in, we should say what it is.
We need to stop judging and hating.