Precisely. Any artist that thinks his mind isn't responsible for the beautiful things they create is doing himself a disservice. Perhaps you will never fully understand your mind, but that's a testament to
the power of your mind, not a sign that a divine being is necessary.
Frank Zappa had an excellent quote about this. When discussing spiritualism in music with a fellow musician, he said: "Look, these are just instruments. Find out what the range is, and start writing." And that's what it is. Writing music is difficult, and requires a degree of brilliance to come out with even a comparatively mediocre song, but there's no magic to it. It takes work and thought. It doesn't take superstition.