The menorah was absolutely one, all of a piece, because truth is one. Although ornamented with numerous buds, flowers, and cups, the entire object was formed from a single piece of gold. By analogy, from the core of truth emerge the Torah and mitzvos as well as all the worlds, both spiritual and physical, which possess colors and variations beyond number; nevertheless, in their source, all things are absolutely one... The menorah was one because the diversity of existence is one. This is the essence of truth, which is one.
(Reb Noson of Breslov)