I don't believe the word "Namaste" by itself is a religious word or has religious connotations in the normal daily usage these days. I believe it is used by people of all/many religious backgrounds in India. I guess sometimes the difference between religion and culture is a fine line.
My religion teaches that the standard preoccupations of people are:
money (or power or ENERGY) food (or sustenance) sex (or connection or RELATIONSHIP)
BUT since so many religions have different "takes" on these matters religions are the source of many arguments and wars, whereas they actually have common threads (which should be their unifying factors).