I am philosophically a non-dualist, by which I mean I accept it mentally as the truth. But I am not a fervent, passionate non-dualist like some people I know.
I believe in a hierarchical universe of various levels. Technically each lower level is less real than the one above, given that it is further from the ultimate source. However, I do believe that what goes on at the material level is very important, that we are called to do certain work here. So we might as well consider the material world as real, to all intents and purposes. Rather than try to escape the material world, as in Buddhism and Hinduism, I believe rather that we are trying to bring heaven (spirit) down to Earth.